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User`s Manual

1. pulse Pulse description sine Sinusoidal source description sin Sinusoidal source description exp Exponential source description pwl Piecewise linear description sffm single freq FM description ac AC magnitude phase vector c Current through current source distof1 f1 input for distortion distof2 f2 input for distortion Isource instance parameters input output de DC value of source acmag AC magnitude acphase AC phase Isource instance parameters output only neg_node Negative node of source pos_node Positive node of source acreal AC real part acimag AC imaginary part function Function of the source order Order of the source function coeffs Coefficients of the source v Voltage across the supply p Power supplied by the source 118 User s Manual Spice3f APPENDIX B MODEL AND DEVICE PARAMETERS B 14 JFET Junction Field effect transistor JFET instance parameters input output off Device initially off ic Initial VDS VGS vector area Area factor ic vds Initial D S voltage ic vgs Initial G S volrage temp Instance temperature JFET instance parameters output only drain node Number of drain node gate node Number of gate node source node drain prime node Number of source node Internal drain node source prime node Internal source node vgs Voltage G S ved Voltage G D ig Current at gate node id Current at drain node is Source current
2. model parameters input output SW Switch model vt Threshold voltage vh Hysteresis voltage ron Resistance when closed roff Resistance when open Switch model parameters output only gon Conductance when closed goff Conductance when open B 23 Tranline Lossless transmission line Tranline instance parameters input only Initial condition vector v1 i1 v2 i2 Tranline instance parameters input output z0 Characteristic impedance ZO null f Frequency td Transmission delay nl Normalized length at frequency given vl Initial voltage at end 1 v2 Initial voltage at end 2 il Initial current at end 1 i2 Initial current at end 2 136 User s Manual Spice3f APPENDIX B MODEL AND DEVICE PARAMETERS Tranline instance parameters output only rel Rel rate of change of deriv for bkpt abs Abs rate of change of deriv for bkpt pos_nodel Positive node of end of t line neg_nodel Negative node of end of t line pos_node2 Positive node of end 2 of t line neg_node2 Negative node of end 2 of t line delays Delayed values of excitation B 24 VCCS Voltage controlled current source VCCS instance parameters input only Initial condition of controlling source VCCS instance parameters input output cont_p_node cont_n_node gain Transconductance of source gain VCCS instance parameters output only pos_node P
3. that divides the device list from the parameter list The old form with v prints the data in a older more verbose pre spice3f format Spice3f User s Manual 79 5 3 46 INTERACTIVE INTERPRETER COMMANDS 5 3 46 Showmod List model parameter values General Form showmod models parameters The showmod command operates like the show command above but prints out model parame ter values The applicable forms for models are a single letter specifying the device type letter wow letter subckt modelname subckt modelname or letter subcircuit modelname 5 3 47 Source Read a Spice3 input file General Form source file For Spice3 Read the Spice3 input file file Nutmeg and Spice3 commands may be included in the file and must be enclosed between the lines control and endc These commands are executed immediately after the circuit is loaded so a control line of ac works the same as the corresponding the circuit The exception to this rule is the file spiceinit Thus a Spice3 command script must begin with a blank line and then with a control line Also any line beginning with the characters is con sidered a control line This makes it possible to imbed commands in Spice3 input files that are ig nored by earlier versions of Spice2 For Nutmeg Reads commands from the file filename Lines beginning with the character are considered comments and ignored 5 3 48 Status Display b
4. General Form plot exprs ylimit ylo yhi xlimit xlo xhi xindices xilo xihi xcompress comp xdelta xdel ydelta ydel xlog ylog loglog vs xname xlabel word ylabel word title word samep linear Plot the given exprs on the screen if you are on a graphics terminal The xlimit and ylimit argu ments determine the high and low x and y limits of the axes respectively The xindices arguments deter mine what range of points are to be plotted everything between the xilo th point and the xihi th point is plotted The xcompress argument specifies that only one out of every comp points should be plotted If an xdelta or a ydelta parameter is present it specifies the spacing between grid lines on the X and Y axis These parameter names may be abbreviated to xl yl xind xcomp xdel and ydel respectively The xname argument is an expression to use as the scale on the x axis If xlog or ylog are present then the X or Y scale respectively is logarithmic loglog is the same as specifying both The xlabel and ylabel arguments cause the specified labels to be used for the X and Y axes respectively If samep is given the values of the other parameters other than xname from the previous plot hardcopy or asciiplot command is used unless re defined on the command line The title argument is used in the place of the plot name at the bottom of the graph The linear keyword is used to override a default log scale pl
5. General form MODEL MNAME TYPE PNAME1 PVAL1 PNAME2 PVAL2 Examples MODEL MOD1 NPN BF 50 IS 1E 13 VBF 50 Most simple circuit elements typically require only a few parameter values However some devices semiconductor devices in particular that are included in SPICE require many parameter values Often many devices in a circuit are defined by the same set of device model parameters For these reasons a set of device model parameters is defined on a separate MODEL line and assigned a unique model name The device element lines in SPICE then refer to the model name For these more complex device types each device element line contains the device name the nodes to which the device is connected and the device model name In addition other optional parameters may be specified for some devices geometric factors and an initial condition see the following section on Transistors and Diodes for more details MNAME in the above is the model name and type is one of the following fifteen types R Semiconductor resistor model C Semiconductor capacitor model SW Voltage controlled switch CSW Current controlled switch URC Uniform distributed RC model LTRA Lossy transmission line model D Diode model NPN NPN BJT model PNP PNP BJT model NJF N channel JFET model PJF P channel JFET model NMOS N channel MOSFET model PMOS P channel MOSFET model NMF N channel MESFET model PMF P channel MESFET model
6. INTERACTIVE INTERPRETER COMMANDS 5 3 55 Unalias Retract an alias General Form unalias word Removes any aliases present for the words 5 3 56 Undefine Retract a definition General Form undefine function Definitions for the named user defined functions are deleted 5 3 57 Unset Clear a variable General Form unset word Clear the value of the specified variable s word 5 3 58 Version Print the version of Spice General Form version version id 5 3 55 Print out the version of nutmeg that is running If there are arguments it checks to make sure that the arguments match the current version of SPICE This is mainly used as a Command line in rawfiles Spice3f User s Manual 83 5 3 59 INTERACTIVE INTERPRETER COMMANDS 5 3 59 Where Identify troublesome node or device General Form where When performing a transient or operating point analysis the name of the last node or device to cause non convergence is saved The where command prints out this information so that you can ex amine the circuit and either correct the problem or make a bug report You may do this either in the middle of a run or after the simulator has given up on the analysis For transient simulation the iplot command can be used to monitor the progress of the analysis When the analysis slows down severly or hangs interrupt the simulator with control C and issue the where command Note that only one
7. Parameter values are defined by appending the parameter name followed by an equal sign and the parameter value Model parameters that are not given a value are assigned the default values given below for each model type Models model parameters and default values are listed in the next section along with the description of device element lines Spice3f User s Manual 9 2 4 CIRCUIT DESCRIPTION SUBCIRCUITS 2 4 SUBCIRCUITS A subcircuit that consists of SPICE elements can be defined and referenced in a fashion similar to device models The subcircuit is defined in the input file by a grouping of element lines the program then automatically inserts the group of elements wherever the subcircuit is referenced There is no limit on the size or complexity of subcircuits and subcircuits may contain other subcircuits An example of subcircuit usage is given in Appendix A 2 4 1 SSUBCKT Line General form SUBCKT subnam N1 lt N2 N3 gt Examples SUBCKT OPAMP 1 2 3 4 A circuit definition is begun with a SUBCKT line SUBNAM is the subcircuit name and N1 N2 are the external nodes which cannot be zero The group of element lines which immediately follow the SUBCKT line define the subcircuit The last line in a subcircuit definition is the ENDS line see below Control lines may not appear within a subcircuit definition however subcircuit definitions may contain anything else including other subcircuit definitions de
8. 28 User s Manual Spice3f CIRCUIT ELEMENTS AND MODELS TRANSMISSION LINES 3 3 3 uses linear interpolation otherwise it uses the default quadratic interpolation TRUNCDONTCUT is a flag that removes the default cutting of the time step to limit errors in the actual calculation of impulse response related quantities COMPACTREL and COMPACTABS are quantities that control the compaction of the past history of values stored for convolution Larger values of these lower accuracy but usually increase simulation speed These are to be used with the TRYTOCOMPACT option described in the OPTIONS section TRUNCNR is a flag that turns on the use of Newton Raphson iterations to determine an appropri ate timestep in the timestep control routines The default is a trial and error procedure by cutting the previ ous timestep in half REL and ABS are quantities that control the setting of breakpoints The option most worth experimenting with for increasing the speed of simulation is REL The default value of 1 is usually safe from the point of view of accuracy but occasionally increases computation time A value greater than 2 eliminates all breakpoints and may be worth trying depending on the nature of the rest of the circuit keeping in mind that it might not be safe from the viewpoint of accuracy Break points may usually be entirely eliminated if it is expected the circuit will not display sharp discontinuities Values between 0 and 1 are usually not require
9. 3 4 7 MOSFETs General form MXXXXXXX ND NG NS NB MNAME lt L VAL gt lt W VAL gt lt AD VAL gt lt AS VAL gt lt PD VAL gt lt PS VAL gt lt NRD VAL gt lt NRS VAL gt lt OFF gt lt IC VDS VGS VBS gt lt TEMP T gt Examples M1 24 2 0 20 TYPE1 M31 2 17 6 10 MODM L 5U W 2U M1 2 9 3 0 MOD1 L 10U W 5U AD 100P AS 100P PD 40U PS 40U ND NG NS and NB are the drain gate source and bulk substrate nodes respectively MNAME is the model name L and W are the channel length and width in meters AD and AS are the areas of the drain and source diffusions in meters Note that the suffix U specifies microns 1e 6 m and P sq microns le 12 m If any of L W AD or AS are not specified default values are used The use of defaults simplifies input file preparation as well as the editing required if device geometries are to be changed PD and PS are the perimeters of the drain and source junctions in meters NRD and NRS designate the equivalent number of squares of the drain and source diffusions these values multiply the sheet resistance RSH speci fied on the MODEL control line for an accurate representation of the parasitic series drain and source resistance of each transistor PD and PS default to 0 0 while NRD and NRS to 1 0 OFF indicates an optional initial condition on the device for dc analysis The optional initial condition specification using IC VDS VGS VBS is intended for use with the U
10. node or device is printed there may be problems with more than one node 5 3 60 Write Write data to a file General Form write file exprs Writes out the expressions to file First vectors are grouped together by plots and written out as such i e if the expression list contained three vectors from one plot and two from another then two plots are written one with three vectors and one with two Additionally if the scale for a vector isn t present it is automatically writ ten out as well The default format is ascii but this can be changed with the set filetype command The default filename is rawspice raw or the argument to the r flag on the command line if there was one and the default expression list is all 5 3 61 Xgraph use the xgraph 1 program for plotting General Form xgraph file exprs plot options The spice3 nutmeg xgraph command plots data like the plot command but via xgraph a popu lar X11 plotting program If file is either temp or tmp a temporary file is used to hold the data while being plotted For available plot options see the plot command All options except for polar or smith plots are support ed 84 User s Manual Spice3f INTERACTIVE INTERPRETER COMMANDS 5 3 61 5 4 CONTROL STRUCTURES 5 4 1 While End General Form while condition statement end While condition an arbitrary algebraic expression is true execute the statements 5 4 2 Repeat
11. slowplot sourcepath spicepath term units INTERACTIVE INTERPRETER VARIABLES The number of digits to print when printing tables of data fourier print col The default precision is 6 digits On the VAX approxi mately 16 decimal digits are available using double precision so numdgt should not be more than 16 If the number is negative one fewer digit is printed to ensure constant widths in tables This should be one of normal comb or point chars normal the de fault causes points to be plotted as parts of connected lines comb causes a comb plot to be done see the description of the combplot variable above point causes each point to be plotted separately the chars are a list of characters that are used for each vector plotted If they are omitted then a default set is used The degree of the polynomial that the plot command should fit to the data If polydegree is N then nutmeg fits a degree N polynomial to every set of N points and draw 10 intermediate points in between each endpoint If the points aren t monotonic then it tries rotating the curve and reducing the degree until a fit is achieved The number of points to interpolate between every pair of points avail able when doing curve fitting The default is 10 The name of the current program argv 0 J oy The prompt with the character replaced by the current event number The default name for rawfiles created The relative tolerance used by t
12. H SUBCKT NAND 1 2 3 X NODES Q1 9 DICLAMP 0 Q2 9 D2CLAMP 0 RB 4 R1 4 Q3 6 R2 8 RC 4 Q4 7 DVBEDROP 10 Q5 3 ENDS NAND SUBCKT ON te NODES X1 le De a af X2 ls lt 23 X3 2 7 9 X4 8 9 10 X5 3 10 11 INPUT a6 1 1 5 2 2 3 6 9 8 0 7 6 10 3 8 0 L NAND GATE INIT o g O MO O O INPUT 2 6 NAND 6 NAND 6 NAND 6 NAND 6 NAND T IONS BINARY ADD OUTPUT VCC EBIT 123 45 6 CARRY IN OUTPUT CARRY OUT User s Manual VCC Spice3f APPENDIX A EXAMPLE CIRCUITS X6 Zad 2 6 NAND X7 101113 6 NAND x8 1213 4 6 NAND XQ LL e Iy A 6 NAND ENDS ONEBIT SUBCKT TWOBIT 12345 67 8 9 x NODES INPUT BITO 2 BIT1 2 OUTPUT BITO BIT1 a CARRY IN CARRY OUT VCC X1 12 7 10 9 ONEBIT X2 3 A L0 368s 9 ONEBI ENDS TWOBIT SUBCKT FOURBIT 12345 678910111213 14 15 NODES INPUT BITO 2 BIT1 2 BIT2 2 BIT3 2 OUTPUT BITO BIT1 BIT2 BIT3 CARRY IN CARRY OUT VCC Xl 1 2 3 4 9101316 15 WOBI x2 5 6 7 811121614 15 WOBIT ENDS FOURBIT DEFINE NOMINAL CIRCUIT MODEL DMOD D MODEL QMOD NPN BF 75 RB 100 CJE 1PF CJC 3PF VCC 99 0 DC 5V VINIA 1 0 PULSE 0 3 0 10NS 10NS 10NS 50NS VINIB 2 0 PULSE 0 3 0 10NS 10NS 20NS 100NS VIN2A 3 0 PULS
13. delay NOCONTROL don t do complex timestep control flag not set set LININTERP use linear interpolation flag not set set MIXEDINTERP use linear when quadratic seems bad not set set COMPACTREL special reltol for history compaction flag RELTOL 1 0e 3 COMPACTABS special abstol for history compaction ABSTOL 1 0e 9 TRUNCNR use Newton Raphson method for flag not set set timestep control TRUNCDONTCUT don t limit timestep to keep flag not set set impulse response errors low The following types of lines have been implemented so far RLC uniform transmission line with series loss only RC uniform RC line LC lossless transmission line and RG distributed series resis tance and parallel conductance only Any other combination will yield erroneous results and should not be tried The length LEN of the line must be specified NOSTEPLIMIT is a flag that will remove the default restriction of limiting time steps to less than the line delay in the RLC case NOCONTROL is a flag that prevents the default limiting of the time step based on convolution error criteria in the RLC and RC cases This speeds up simulation but may in some cases reduce the accuracy of results LININTERP is a flag that when specified will use linear interpola tion instead of the default quadratic interpolation for calculating delayed signals MIXEDINTERP is a flag that when specified uses a metric for judging whether quadratic interpolation is not applicable and if so
14. or the last number commands typed at the keyboard Note in Spice3 ver sion 3a7 and earlier all commands including ones read from files were saved 5 3 20 Iplot Incremental plot General Form iplot node Incrementally plot the values of the nodes while Spice3 runs The iplot command can be used with the where command to find trouble spots in a transient simulation 5 3 21 Jobs List active asynchronous spice runs General Form jobs Report on the asynchronous SPICE 3 jobs currently running Nutmeg checks to see if the jobs are finished every time you execute a command If it is done then the data is loaded and becomes available 5 3 22 Let Assign a value to a vector General Form let name expr Creates a new vector called name with the value specified by expr an expression as described above If expr is a zero length vector then the vector becomes undefined Individual elements of a vector may be modified by appending a subscript to name ex name 0 If there are no arguments let is the same as display 70 User s Manual Spice3f INTERACTIVE INTERPRETER COMMANDS 5 3 23 5 3 23 Linearize Interpolate to a linear scale General Form linearize vec Create a new plot with all of the vectors in the current plot or only those mentioned if argu ments are given The new vectors are interpolated onto a linear time scale which is determined by the values of tstep tstart and tstop in the
15. qgs Gate Source charge storage qgd Gate Drain charge storage qgb Gate Bulk charge storage qbd Bulk Drain charge storage qbs Bulk Source charge storage p Instaneous power Mos6 model parameters input only nmos N type MOSfet model pmos P type MOSfet model Spice3f User s Manual 133 APPENDIX B MODEL AND DEVICE PARAMETERS Mos6 model parameters input output vto Threshold voltage vtO null kv Saturation voltage factor nv Saturation voltage coeff kc Saturation current factor nc Saturation current coeff nvth Threshold voltage coeff ps Sat current modification par gamma Bulk threshold parameter gammal Bulk threshold parameter 1 sigma Static feedback effect par phi Surface potential lambda Channel length modulation param lambda0 Channel length modulation param 0 lambda1 Channel length modulation param 1 rd Drain ohmic resistance TS Source ohmic resistance cbd B D junction capacitance cbs B S junction capacitance is Bulk junction sat current pb Bulk junction potential cgso Gate source overlap cap cgdo Gate drain overlap cap cgbo Gate bulk overlap cap rsh Sheet resistance cj Bottom junction cap per area mj Bottom grading coefficient cjsw Side junction cap per area mjsw Side grading coefficient js Bulk jct sat current density ld Lateral diffusion tox Oxide thickness u0 Surface mobility uo null fc Forward bias jct fi
16. 0 2 N and N are the positive and negative nodes respectively MNAME is the model name AREA is the area factor and OFF indicates an optional starting condition on the device for dc analysis If the area factor is omitted a value of 1 0 is assumed The optional initial condition specification using IC VD is intended for use with the UIC option on the TRAN control line when a transient analysis is desired start ing from other than the quiescent operating point The optional TEMP value is the temperature at which this device is to operate and overrides the temperature specification on the OPTION control line Spice3f User s Manual 31 3 4 2 CIRCUIT ELEMENTS AND MODELS TRANSISTORS AND DIODES 3 4 2 Diode Model D The dc characteristics of the diode are determined by the parameters IS and N An ohmic resistance RS is included Charge storage effects are modeled by a transit time TT and a nonlinear depletion layer capacitance which is determined by the parameters CJO VJ and M The temperature dependence of the saturation current is defined by the parameters EG the energy and XTI the saturation current temperature exponent The nominal temperature at which these parameters were measured is TNOM which defaults to the circuit wide value specified on the OPTIONS control line Reverse breakdown is modeled by an ex ponential increase in the reverse diode current and is determined by the parameters BV and IBV both of whi
17. 2 0 DISTOF2 0 01 IIN1 1 5 AC 1 DISTOF1 DISTOF2 0 001 N and N are the positive and negative nodes respectively Note that voltage sources need not be grounded Positive current is assumed to flow from the positive node through the source to the negative node A current source of positive value forces current to flow out of the N node through the source and into the N node Voltage sources in addition to being used for circuit excitation are the ammeters for SPICE that is zero valued voltage sources may be inserted into the circuit for the purpose of measuring current They of course have no effect on circuit operation since they represent short circuits DC TRAN is the dc and transient analysis value of the source If the source value is zero both for dc and transient analyses this value may be omitted If the source value is time invariant e g a power sup ply then the value may optionally be preceded by the letters DC ACMAG is the ac magnitude and ACPHASE is the ac phase The source is set to this value in the ac analysis If ACMAG is omitted following the keyword AC a value of unity is assumed If ACPHASE is omitted a value of zero is assumed If the source is not an ac small signal input the keyword AC and the ac values are omitted DISTOF1 and DISTOF2 are the keywords that specify that the independent source has distortion inputs at the frequencies F1 and F2 respectively see the description of the DIS
18. Calculates the derivative of the given vector This uses numeric differentiation by interpolating a polynomial and may not produce satisfactory results particularly with iterated dif ferentiation The implementation only caculates the diriva tive with respect to the real componant of that vector s scale A vector may be either the name of a vector already defined or a floating point number a scalar A number may be written in any format acceptable to SPICE such as 14 6Meg or 1 231le 4 Note that you can either use scientific notation or one of the abbreviations like MEG or G but not both As with SPICE a number may have trailing alphabetic characters after it The notation expr num denotes the num th element of expr For multi dimensional vectors a vector of one less dimension is returned Also for multi dimensional vectors the notation expr m n will return the nth element of the mth subvector To get a subrange of a vector use the form expr lower upper To reference vectors in a plot that is not the current plot see the setplot command below the nota tion plotname vecname can be used Either a plotname or a vector name may be the wildcard all If the plotname is all matching vectors from all plots are specified and if the vector name is all all vectors in the specified plots are referenced Note that you may not use binary operations on expressions involving wildcards it is not obvious what all all should d
19. End General Form repeat number statement end Execute the statements number times or forever if no argument is given 5 4 3 Dowhile End General Form dowhile condition statement end The same as while except that the condition is tested after the statements are executed Spice3f User s Manual 85 5 4 4 INTERACTIVE INTERPRETER CONTROL STRUCTURES 5 4 4 Foreach End General Form foreach var value statement end The statements are executed once for each of the values each time with the variable var set to the current one var can be accessed by the var notation see below 5 4 5 If Then Else General Form if condition statement else statement end If the condition is non zero then the first set of statements are executed otherwise the second set The else and the second set of statements may be omitted 5 4 6 Label General Form label word If a statement of the form goto word is encountered control is transferred to this point other wise this is a no op 86 User s Manual Spice3f INTERACTIVE INTERPRETER CONTROL STRUCTURES 5 4 7 5 4 7 Goto General Form goto word If a statement of the form label word is present in the block or an enclosing block control is transferred there Note that if the label is at the top level it must be before the goto statement i e a forward goto may occur only within a block 5 4 8 Continue Gener
20. In or sqrt becomes less than zero the absolute value of the argument is used If a divisor becomes zero or the argument of log or In becomes zero an error will result Other problems may occur when the argument for a function in a partial derivative enters a region where that function is undefined To get time into the expression you can integrate the current from a constant current source with a capacitor and use the resulting voltage don t forget to set the initial voltage across the capacitor Non linear resistors capacitors and inductors may be synthesized with the nonlinear dependent source Non linear resistors are obvious Non linear capacitors and inductors are implemented with their linear counter parts by a change of variables implemented with the nonlinear dependent source The following subcircuit will implement a nonlinear capacitor Subckt nlcap pos neg Bx calculate f input voltage Bx 1 0 v v pos neg Cx linear capacitance Cx 2 0 Bl Vx Ammeter to measure current into the capacitor Vx 2 1 DC OVolts Drive the current through Cx back into the circuit FX pos neg Vx 1 ends Non linear inductors are similar 26 User s Manual Spice3f CIRCUIT ELEMENTS AND MODELS TRANSMISSION LINES 3 3 3 3 TRANSMISSION LINES 3 3 1 Lossless Transmission Lines General form TXXXXXXX N1 N2 N3 N4 ZO VALUE lt TD VALUE gt lt F FREQ lt NL NRMLEN gt gt lt IC V1 Il V2 12 gt E
21. PLOT PLTYPE OV1 lt PLO1 PHI1 gt lt OV2 lt PLO2 PHI2 gt OV8 gt Examples PLOT DC V 4 V 5 V 1 PLOT TRAN V 17 5 2 5 I VIN V 17 1 9 LOT AC VM 5 VM 31 24 VDB 5 VP 5 PLOT DISTO HD2 HD3 R SIM2 PLOT TRAN V 5 3 V 4 0 5 V 7 0 10 D P D D The Plot line defines the contents of one plot of from one to eight output variables PLTYPE is the type of analysis DC AC TRAN NOISE or DISTO for which the specified outputs are desired The syntax for the OVI is identical to that for the PRINT line and for the plot command in the in teractive mode The overlap of two or more traces on any plot is indicated by the letter X When more than one output variable appears on the same plot the first variable specified is printed as well as plotted If a printout of all variables is desired then a companion PRINT line should be included There is no limit on the number of PLOT lines specified for each type of analysis Spice3f User s Manual 57 4 4 4 ANALYSES AND OUTPUT CONTROL BATCH OUTPUT 4 4 4 FOUR Fourier Analysis of Transient Analysis Output General form FOUR FREQ OV1 lt OV2 OV3 gt Examples FOUR 100K V 5 The Four or Fourier line controls whether SPICE performs a Fourier analysis as a part of the transient analysis FREQ is the fundamental frequency and OV1 are the output variables for which the analysis is desired The Fourier analysis i
22. RD and RS in ohms or RSH in ohms sq the latter being multiplied by the number of squares NRD and NRS input on the device line A discontinuity in the MOS level 3 model with respect to the KAPPA parameter has been detected see 10 The supplied fix has been implemented in Spice3f2 and later Since this fix may affect parame ter fitting the option BADMOS3 may be set to use the old implementation see the section on simulation variables and the OPTIONS line 38 User s Manual Spice3f CIRCUIT ELEMENTS AND MODELS TRANSISTORS AND DIODES 3 4 8 SPICE level 1 2 3 and 6 parameters name parameter units default example 1 LEVEL model index 1 2 VTO zero bias threshold voltage Vro V 0 0 1 0 3 KP transconductance parameter A V 2 0e 5 3 1e 5 4 GAMMA bulk threshold parameter y ee 0 0 0 37 5 PHI surface potential V 0 6 0 65 6 LAMBDA channel length modulation MOS1 and MOS2 only A 1 V 0 0 0 02 7 RD drain ohmic resistance Q 0 0 1 0 8 RS source ohmic resistance Q 0 0 1 0 9 CBD zero bias B D junction capacitance F 0 0 20fF 10 CBS zero bias B S junction capacitance F 0 0 20fF 11 IS bulk junction saturation current Ix A 1 0e 14 1 0e 15 12 PB bulk junction potential V 0 8 0 87 13 CGSO gate source overlap capacitance per meter channel width F m 0 0 4 0e 11 14 CGDO gate drain overlap capacitance per meter channel width F m 0 0 4 0e 11 15 CGBO gate bulk overlap capacitance per meter channel length F m 0 0 2 0
23. Research Laboratory University of California Berkeley October 1990 Soyeon Park Analysis and SPICE implementation of High Temperature Effects on MOSFET Master s thesis University of California Berkeley December 1986 Clement Szeto Simulator of Temperature Effects in MOSFETs STEIM Master s thesis University of California Berkeley May 1988 J S Roychowdhury and D O Pederson Efficient Transient Simulation of Lossy Interconnect Proc of the 28th ACM IEEE Design Automation Conference June 17 21 1991 San Francisco A E Parker and D J Skellern An Improved FET Model for Computer Simulators IEEE Trans CAD vol 9 no 5 pp 551 553 May 1990 R Saleh and A Yang Editors Simulation and Modeling IEEE Circuits and Devices vol 8 no 3 pp 7 8 and 49 May 1992 H Statz et al GaAs FET Device and Circuit Simulation in SPICE IEEE Transactions on Electron Devices V34 Number 2 February 1987 pp160 169 Spice3f User s Manual 97 98 User s Manual Spice3f A APPENDIX A EXAMPLE CIRCUITS A 1 Circuit 1 Differential Pair The following deck determines the dc operating point of a simple differential pair In addition the ac small signal response is computed over the frequency range 1Hz to 1 OOMEGHz SIMPLE DIFFERENTIAL PAIR VEE TS CO 12 VEE 8 0 12 VIN 1 0 AC 1 RS1 1 2 1K RS2 6 0 1K Q1 3 2 4 MOD1 Q2 5 6 4 MOD1 REL V 3 10K REZ 7 5 10K RE 4 8
24. Set Initial Conditions General form IC V NODNUM VAL V NODNUM VAL Examples IC V 11 5 V 4 5 V 2 2 2 The IC line is for setting transient initial conditions It has two different interpretations depending on whether the UIC parameter is specified on the TRAN control line Also one should not confuse this line with the NODESET line The INODESET line is only to help dc convergence and does not affect final bias solution except for multi stable circuits The two interpretations of this line are as follows 1 When the UIC parameter is specified on the TRAN line then the node voltages specified on the IC control line are used to compute the capacitor diode BJT JFET and MOSFET initial conditions This is equivalent to specifying the IC parameter on each device line but is much more convenient The IC parameter can still be specified and takes precedence over the IC values Since no dc bias initial tran sient solution is computed before the transient analysis one should take care to specify all dc source vol tages on the IC control line if they are to be used to compute device initial conditions 2 When the UIC parameter is not specified on the TRAN control line the dc bias initial transient solu tion is computed before the transient analysis In this case the node voltages specified on the IC control line is forced to the desired initial values during the bias solution During transient analysis the c
25. V as V qa sens of mobility to drain bias at Vy Vaq sens of velocity saturation effect on drain bias at Va Vaa gate oxide thickness temperature at which parameters were measured measurement bias range gate drain overlap capacitance per meter channel width gate source overlap capacitance per meter channel width gate bulk overlap capacitance per meter channel length gate oxide capacitance charge model flag zero bias subthreshold slope coefficient sens of subthreshold slope to substrate bias sens of subthreshold slope to drain bias drain and source diffusion sheet resistance source drain junction current density built in potential of source drain junction Grading coefficient of source drain junction built in potential of source drain junction sidewall grading coefficient of source drain junction sidewall Source drain junction capacitance per unit area source drain junction sidewall capacitance per unit length source drain junction default width Source drain junction length reduction units I w cm2 V2 s cm V s cm V s umV i um C XPART 0 selects a 40 60 drain source charge partition in saturation while XPART 1 selects a 0 100 drain source charge partition ND NG and NS are the drain gate and source nodes respectively MNAME is the model name AREA is the area factor and OFF indicates an optional initial condition on the device for dc analysis If the area factor is omitte
26. analysis assumes a small signal DC slowly varying input Spice3f User s Manual 81 5 3 52 INTERACTIVE INTERPRETER COMMANDS 5 3 52 Trace Trace nodes General Form trace node For every step of an analysis the value of the node is printed Several traces may be active at once Tracing is not applicable for all analyses To remove a trace use the delete command 5 3 53 Tran Perform a transient analysis General Form tran TstepTstop Tstart Tmax UIC Perform a transient analysis See the previous sections of this manual for more details 5 3 54 Transpose Swap the elements in a multi dimensional data set General Form transpose vector vector This command transposes a multidimensional vector No analysis in Spice3 produces multidi mensional vectors although the DC transfer curve may be run with two varying sources You must use the reshape command to reform the one dimensional vectors into two dimensional vectors In addition the default scale is incorrect for plotting You must plot versus the vector corresponding to the second source but you must also refer only to the first segment of this second source vector For example circuit to produce the tranfer characteristic of a MOS transistor spice3 gt dc vgg 05 1 vdd 0 5 1 spice3 gt plot i vdd spice3 gt reshape all 6 6 spice3 gt transpose i vdd v drain spice3 gt plot i vdd vs v drain 0 82 User s Manual Spice3f
27. and not evaluated as numbers thus 0 and 00 are distinct nodes in SPICE3 but not in SPICE2 The circuit cannot contain a loop of vol tage sources and or inductors and cannot contain a cut set of current sources and or capacitors Each node in the circuit must have a dc path to ground Every node must have at least two connections except for transmission line nodes to permit unterminated transmission lines and MOSFET substrate nodes which have two internal connections anyway Spice3f User s Manual 7 2 1 CIRCUIT DESCRIPTION GENERAL STRUCTURE AND CONVENTIONS 2 2 TITLE LINE COMMENT LINES AND END LINE 2 2 1 Title Line Examples POWER AMPLIFIER CIRCUIT TEST OF CAM CELL The title line must be the first in the input file Its contents are printed verbatim as the heading for each section of output 2 2 2 END Line Examples END The End line must always be the last in the input file Note that the period is an integral part of the name 2 2 3 Comments General Form lt any comment gt Examples RF 1K Gain should be 100 Check open loop gain and phase margin The asterisk in the first column indicates that this line is a comment line Comment lines may be placed anywhere in the circuit description Note that SPICE3 also considers any line with leading white space to be a comment 8 User s Manual Spice3f CIRCUIT DESCRIPTION DEVICE MODELS 2 3 2 3 DEVICE MODELS
28. and the specifications of the process If VALUE is specified it defines the capacitance If MNAME is specified then the capacitance is calculated from the process information in the model MNAME and the given LENGTH and WIDTH If VALUE is not specified then MNAME and LENGTH must be specified If WIDTH is not specified then it is taken from the default width given in the model Either VALUE or MNAME LENGTH and WIDTH may be specified but not both sets Spice3f User s Manual 15 3 1 6 CIRCUIT ELEMENTS AND MODELS ELEMENTARY DEVICES 3 1 6 Semiconductor Capacitor Model C The capacitor model contains process information that may be used to compute the capacitance from strictly geometric information name parameter units default example CJ junction bottom capacitance F meters Se 5 CJSW junction sidewall capacitance F meters 2e 11 DEFW default device width meters le 6 2e 6 NARROW narrowing due to side etching meters 0 0 le 7 The capacitor has a capacitance computed as CAP CJ LENGTH NARROW WIDTH NARROW 2 CJSW LENGTH WIDTH 2 NARROW 3 1 7 Inductors General form LYYYYYYY N N VALUE lt IC INCOND gt Examples LLINK 42 69 1UH LSHUNT 23 51 10U IC 15 7MA N and N are the positive and negative element nodes respectively VALUE is the inductance in Henries The optional initial condition is the initial time zero value of inductor current in Amps that flows from N thr
29. commands given all outputs are saved When the keyword all appears in the save command all default values node voltages and voltage source currents are saved in addition to any other values listed 5 3 38 Sens Run a sensitivity analysis General Form sens output_variable sens output_variable ac DEC OCT LIN N Fstart Fstop Perform a Sensitivity analysis output_variable is either a node voltage ex v 1 or v A out or a current through a voltage source ex i vtest The first form calculates DC sensi tivities the second form calculates AC sensitivies The output values are in dimensions of change in output per unit change of input as opposed to percent change in output or per percent change of in put 5 3 39 Set Set the value of a variable General Form set word set word value Set the value of word to be value if it is present You can set any word to be any value numeric or string If no value is given then the value is the boolean true The value of word may be inserted into a command by writing word If a variable is set to a list of values that are enclosed in parentheses which must be separated from their values by white space the value of the variable is the list The variables used by nutmeg are listed in the following section Spice3f User s Manual 77 5 3 40 INTERACTIVE INTERPRETER COMMANDS 5 3 40 Setcirc Change the current circuit General Form
30. failure occurs the program terminates the job Failure to converge in dc analysis is usually due to an error in specifying circuit connections element values or model parameter values Regenerative switching circuits or circuits with positive feedback prob ably will not converge in the dc analysis unless the OFF option is used for some of the devices in the feed back path or the INODESET control line is used to force the circuit to converge to the desired state 6 User s Manual Spice3f 2 CIRCUIT DESCRIPTION 2 1 GENERAL STRUCTURE AND CONVENTIONS The circuit to be analyzed is described to SPICE by a set of element lines which define the circuit topology and element values and a set of control lines which define the model parameters and the run controls The first line in the input file must be the title and the last line must be END The order of the remaining lines is arbitrary except of course that continuation lines must immediately follow the line being continued Each element in the circuit is specified by an element line that contains the element name the circuit nodes to which the element is connected and the values of the parameters that determine the electrical characteristics of the element The first letter of the element name specifies the element type The format for the SPICE element types is given in what follows The strings XXXXXXX YYYYYYY and ZZZZZZZ denote arbitrary alphanumeric strings For example
31. igd Current G D gm Transconductance gds Conductance D S ggs Conductance G S ggd Conductance G D qgs Charge storage G S junction qgd Charge storage G D junction cqgs Capacitance due to charge storage G S junction cqgd Capacitance due to charge storage G D junction p Power dissipated by the JFET JFET model parameters input output njf N type JFET model pjf P type JFET model vtO Threshold voltage vto null beta Transconductance parameter lambda Channel length modulation param rd Drain ohmic resistance TS Source ohmic resistance cgs G S junction capactance continued Spice3f User s Manual 119 APPENDIX B MODEL AND DEVICE PARAMETERS JFET model input output parameters continued ced G D junction cap pb Gate junction potential is Gate junction saturation current fc Forward bias junction fit parm b Doping tail parameter tnom parameter measurement temperature kf Flicker Noise Coefficient af Flicker Noise Exponent JFET model parameters output only type N type or P type JFET model gd Drain conductance gs Source conductance B 15 LTRA Lossy transmission line LTRA instance parameters input only Initial condition vector v1 i1 v2 i2 LTRA instance parameters input output vl Initial voltage at end 1 v2 Initial voltage at end 2 il Initial current at end 1 i2 Initial current at end 2 LTRA instance parameter
32. of the source input values 22 at intermediate values of time is determined by using linear interpolation on the User s Manual Spice3f CIRCUIT ELEMENTS AND MODELS VOLTAGE AND CURRENT SOURCES 3 2 1 5 3 2 1 5 Single Frequency FM General Form SFFM VO VA FC MDI FS Examples V1 12 0 SFFM O 1M 20K 5 1K parameter default value units VO offset Volts or Amps VA amplitude Volts or Amps FC carrier frequency 1 TSTOP Hz MDI modulation index FS signal frequency 1 TSTOP Hz The shape of the waveform is described by the following equation VO Vo V sin 2 n FC t MDI sin 2 x FS o 3 2 2 Linear Dependent Sources SPICE allows circuits to contain linear dependent sources characterized by any of the four equations i gv v ev i fi v hi where g e f and h are constants representing transconductance voltage gain current gain and transresis tance respectively Spice3f User s Manual 23 3 2 2 1 CIRCUIT ELEMENTS AND MODELS VOLTAGE AND CURRENT SOURCES 3 2 2 1 Linear Voltage Controlled Current Sources General form GXXXXXXX N N NC NC VALUE Examples G1 2 05 0 0 1MMHO N and N are the positive and negative nodes respectively Current flow is from the positive node through the source to the negative node NC and NC are the positive and negative control ling nodes respectively VALUE is the transconductance in mhos 3 2 2 2 Linear Voltage Controlled Voltage Sources Gene
33. subcircuits In any spice input file the include line may be used to copy some other file as if that second file appeared in place of the include line in the original file There is no res triction on the file name imposed by spice beyond those imposed by the local operating system 12 User s Manual Spice3f 3 CIRCUIT ELEMENTS AND MODELS Data fields that are enclosed in less than and greater than signs lt gt are optional All indicated punctuation parentheses equal signs etc is optional but indicate the presence of any delimiter Further future implementations may require the punctuation as stated A consistent style adhering to the punctua tion shown here makes the input easier to understand With respect to branch voltages and currents SPICE uniformly uses the associated reference convention current flows in the direction of voltage drop 3 1 ELEMENTARY DEVICES 3 1 1 Resistors General form RXXXXXXX N1 N2 VALUE Examples R1 1 2 100 RCI 12 17 1K N1 and N2 are the two element nodes VALUE is the resistance in ohms and may be positive or negative but not zero 3 1 2 Semiconductor Resistors General form RXXXXXXX N1 N2 lt VALUE gt lt MNAME gt lt L LENGTH gt lt W WIDTH gt lt TEMP T gt Examples RLOAD 2 10 10K RMOD 3 7 RMODEL L 10u W 1u This is the more general form of the resistor presented in section 6 1 and allows the modeling of temperature effects a
34. sweep analysis General Form de Source Name Vstart Vstop Vincr Source2 Vstart2 Vstop2 Vincr2 Do a dc transfer curve analysis See the previous sections of this manual for more details 5 3 10 Define Define a function General Form define function argl arg2 expression Define the user definable function with the name function and arguments arg arg 2 to be expression which may involve the arguments When the function is later used the arguments it is given are substituted for the formal arguments when it is parsed If expression is not present any de finition for function is printed and if there are no arguments to define then all currently active defini tions are printed Note that you may have different functions defined with the same name but dif ferent arities Some useful definitions are define max x y x gt y x x lt y y define min x y x lt y x x gt y 5 3 11 Delete Remove a trace or breakpoint General Form delete debug number Delete the specified breakpoints and traces The debug numbers are those shown by the status command unless you do status gt file in which case the debug numbers are not printed Spice3f User s Manual 67 5 3 11 INTERACTIVE INTERPRETER COMMANDS 5 3 12 Diff Compare vectors General Form diff plotl plot2 vec Compare all the vectors in the specified plots or only the named vectors if any are given There are
35. the MOSFET device line Two different forms of initial conditions may be specified for some devices The first form is included to improve the dc convergence for circuits that contain more than one stable state If a device is specified OFF the dc operating point is determined with the terminal voltages for that device set to zero After convergence is obtained the program continues to iterate to obtain the exact value for the terminal voltages If a circuit has more than one dc stable state the OFF option can be used to force the solution to correspond to a desired state If a device is specified OFF when in reality the device is conducting the pro gram still obtains the correct solution assuming the solutions converge but more iterations are required since the program must independently converge to two separate solutions The NODESET control line serves a similar purpose as the OFF option The NODESET option is easier to apply and is the preferred means to aid convergence The second form of initial conditions are specified for use with the transient analysis These are true initial conditions as opposed to the convergence aids above See the description of the IC control line and the TRAN control line for a detailed explanation of initial conditions 3 4 1 Junction Diodes General form DXXXXXXX N N MNAME lt AREA gt lt OFF gt lt IC VD gt lt TEMP T gt Examples DBRIDGE 2 10 DIODE1 DCLMP 3 7 DMOD 3 0 IC
36. the directories in the sourcepath list are searched in order for the file If it is found it is read in as a command file as if it were sourced Before it is read however the variables argc and argv are set to the number of words fol lowing the filename on the command line and a list of those words respectively After the file is finished these variables are unset Note that if a command file calls another it must save its argv and argc since they are altered Also command files may not be re entrant since there are no local variables Of course the procedures may explicitly manipulate a stack This way one can write scripts analogous to shell scripts for nutmeg and Spice3 Note that for the script to work with Spice3 it must begin with a blank line or whatever else since it is thrown away and then a line with control on it This is an unfortunate result of the source command being used for both circuit input and command file execution Note also that this allows the user to merely type the name of a circuit file as a command and it is automatically run The commands are executed immediately without running any analyses that may be spicified in the circuit to execute the analyses before the script executes include a run command in the script There are various command scripts installed in usr local ib spice scripts or whatever the path is on your machine and the default sourcepath includes this directory so you can use th
37. x the device line is written xname nodel node2 subcktname where the nodes are the node names that replace the formal parameters on the subckt line All nodes that are not formal parameters are prepended with the name given to the instance and a as are the names of the devices in the subcircuit If there are several nested subcircuits node and device names look like instances of subcircuits instead of x Nutmeg occasionally checks to see if it is getting close to running out of space and warns the user if this is the case This is more likely to be useful with the SPICE front end C shell type quoting with and and backquote substitution may be used Within single quotes no further substitution like history substitution is done and within double quotes the words are kept together but further substitution is done Any text between backquotes is replaced by the result of execut ing the text as a command to the shell Tenex style set filec in the 4 3 C shell command filename and keyword completion is possible If EOF control D is typed after the first character on the line a list of the commands or possible argu ments is printed If it is alone on the line it exits nutmeg If escape is typed then nutmeg trys to complete what the user has already typed To get a list of all commands the user should type lt space gt D The values of variables may be used in commands by writing va
38. 1 INTRODUCTION SPICE is a general purpose circuit simulation program for nonlinear dc nonlinear transient and linear ac analyses Circuits may contain resistors capacitors inductors mutual inductors independent vol tage and current sources four types of dependent sources lossless and lossy transmission lines two separate implementations switches uniform distributed RC lines and the five most common semiconduc tor devices diodes BJTs JEETs MESFETs and MOSFETs The SPICE3 version is based directly on SPICE 2G 6 While SPICE3 is being developed to include new features it continues to support those capabilities and models which remain in extensive use in the SPICE2 program SPICE has built in models for the semiconductor devices and the user need specify only the per tinent model parameter values The model for the BJT is based on the integral charge model of Gummel and Poon however if the Gummel Poon parameters are not specified the model reduces to the simpler Ebers Moll model In either case charge storage effects ohmic resistances and a current dependent out put conductance may be included The diode model can be used for either junction diodes or Schottky bar rier diodes The JFET model is based on the FET model of Shichman and Hodges Six MOSFET models are implemented MOS1 is described by a square law I V characteristic MOS2 1 is an analytical model while MOS3 1 is a semi empirical model MOS6 2 is a simple ana
39. 10K MODEL MOD1 NPN BF 50 VAF 50 IS 1 E 12 RB 100 CJC 5PF TF 6NS TF V 5 VIN AC DEC 10 1 100MEG A 2 Circuit 2 MOSFET Characterization The following deck computes the output characteristics of a MOSFET device over the range 0 10V for VDS and 0 5V for VGS T MOS OUTPUT CHARACTERISTICS OPTIONS NODE NOPAGE VDS 3 0 VGS 2 0 M1 1 2 O 0 MOD1 L 4U W 6U AD 10P AS 10P VIDS MEASURES ID WE COULD HAVE USED VDS BUT ID WOULD BE VIDS 3 1 MODEL MOD1 NMOS VTO 2 NSUB 1 0E15 UO 550 DC VDS 010 5 VGS 05 1 END 7 zj Z EGATIV Spice3f User s Manual 99 A 3 Circuit 3 RTL Inverter APPENDIX A EXAMPLE CIRCUITS The following deck determines the dc transfer curve and the transient pulse response of a simple RTL inverter The input is a pulse from 0 to 5 Volts with delay rise and fall times of 2ns and a pulse width of 30ns The transient interval is 0 to 100ns with printing to be done every nanosecond R 0 5 2NS 2NS 2NS 30NS Q1 NPN BF 20 RB 100 TF 1NS CJC SIMPLE RTL INVERTE VCC 4 0 5 VIN 1 0 PULSE RB 1 2 10K Ql 3 2 0 Q1 RC 3 4 1K MODEL DC VIN 0 5 0 1 TRAN 1NS 100NS END A 4 Circuit 4 Four Bit Binary Adder 2PF The following deck simulates a four bit binary adder using several subcircuits to describe various pieces of the overall circuit 100 ADD SUBCIRCUIT D ER 4 BIT AL EF F
40. 3 4 v 2 v 1 B1 3 4 I 17 B1 3 4 V exp pi7i vdd N is the positive node and N is the negative node The values of the V and I parameters determine the voltages and currents across and through the device respectively If I is given then the device is a current source and if V is given the device is a voltage source One and only one of these parameters must be given The small signal AC behavior of the nonlinear source is a linear dependent source or sources with a proportionality constant equal to the derivative or derivatives of the source at the DC operating point The expressions given for V and I may be any function of voltages and currents through voltage sources in the system The following functions of real variables are defined abs asinh cosh sin acos atan exp sinh acosh atanh In sqrt asin cos log tan The function u is the unit step function with a value of one for arguments greater than one and a value of zero for arguments less than zero The function uramp is the integral of the unit step for an Spice3f User s Manual 25 3 2 3 CIRCUIT ELEMENTS AND MODELS VOLTAGE AND CURRENT SOURCES input x the value is zero if x is less than zero or if x is greater than zero the value is x These two functions are useful in sythesizing piece wise non linear functions though convergence may be adversely affected The following standard operators are defined E unary If the argument of log
41. ARROW W NARROW DEFW is used to supply a default value for W if one is not specified for the device If either RSH or L is not specified then the standard default resistance value of 1k Q is used TNOM is used to override the circuit wide value given on the OPTIONS control line where the parameters of this model have been measured at a different temperature After the nominal resistance is calculated it is adjusted for tempera ture by the formula R T R To 1 TC1 T To TC2 T T 14 User s Manual Spice3f CIRCUIT ELEMENTS AND MODELS ELEMENTARY DEVICES 3 1 4 Capacitors General form CXXXXXXXK N N VALUE Examples CBYB 13 0 TUF cosc 17 23 10U IC 3V lt IC INCOND gt 3 1 4 N and N are the positive and negative element nodes respectively WALUE is the capaci tance in Farads The optional initial condition is the initial time zero value of capacitor voltage in Volts Note that the initial conditions if any apply only if the UIC option is specified on the TRAN control line 3 1 5 Semiconductor Capacitors General form CXXXXXXX N1 N2 lt VALU Examples CLOAD 2 10 10P E gt lt MNAM E gt lt L LI ENGTH gt lt W WIDTH gt lt IC VAL gt CMOD 3 7 CMODEL L 10u W 1u This is the more general form of the Capacitor presented in section 6 2 and allows for the calculation of the actual capacitance value from strictly geometric information
42. E 0 3 0 10NS 10NS 40NS 200NS VIN2B 4 0 PULSE 0 3 0 10NS 10NS 80NS 400NS VIN3A 5 0 PULSE 0 3 0 10NS 10NS 160NS 800NS VIN3B 6 0 PULSE 0 3 0 10NS 10NS 320NS 1600NS VIN4A 7 0 PULSE 0 3 0 10NS 10NS 640NS 3200NS VIN4B 8 0 PULSE 0 3 0 10NS 10NS 1280NS 6400NS X1 12 3 4 5 6 FT 8 GY 10 11 12 0 13 99 FOURBIT RBITO 9 0 1K RBIT1 10 0 1K RBIT2 id r0 1K RBIT3 12 0 1K RCOUT 13 0 1K FOR THOSE WITH MONEY AND MEMORY TO BURN TRAN 1NS 6400NS END T Spice3f User s Manual 101 APPENDIX A EXAMPLE CIRCUITS A 5 Circuit 5 Transmission Line Inverter The following deck simulates a transmission line inverter Two transmission line elements are re quired since two propagation modes are excited In the case of a coaxial line the first line T1 models the inner conductor with respect to the shield and the second line T2 models the shield with respect to the outside world 102 TRANSMISSION LINE 7 INVERTER V1 1 0 R1 H2 X1 2 70x Oy 4 R2 4 0 SUBCKT TLINE 1 2 Tl 1 2 3 4 T2 2 0 4 0 ENDS TLINE TRAN 0 1NS 20NS END PULSE 0O 1 0 0 1N 50 TLINE 50 3 4 Z0 50 TD 1 5NS Z0 100 TD 1NS User s Manual Spice3f B APPENDIX B MODEL AND DEVICE PARAMETERS The following tables summarize the parameters available on each of the devices and models in note that for some systems with limited memory output parameters are not available T
43. ENTS AND MODELS ELEMENTARY DEVICES 3 1 10 Switch Model SW CSW The switch model allows an almost ideal switch to be described in SPICE The switch is not quite ideal in that the resistance can not change from 0 to infinity but must always have a finite positive value By proper selection of the on and off resistances they can be effectively zero and infinity in comparison to other circuit elements The parameters available are name parameter units default switch VT threshold voltage Volts 0 0 S IT threshold current Amps 0 0 W VH hysteresis voltage Volts 0 0 S IH hysteresis current Amps 0 0 W RON on resistance Q 1 0 both ROFF off resistance Q 1 GMIN both See the OPTIONS control line for a description of GMIN its default value results in an off resistance of 1 0e 12 ohms The use of an ideal element that is highly nonlinear such as a switch can cause large discontinuities to occur in the circuit node voltages A rapid change such as that associated with a switch changing state can cause numerical roundoff or tolerance problems leading to erroneous results or timestep difficulties The user of switches can improve the situation by taking the following steps First it is wise to set ideal switch impedances just high or low enough to be negligible with respect to other circuit elements Using switch impedances that are close to ideal in all cases aggravates the prob lem of discontinuities mentioned above Of course when
44. IC option on the TRAN control line when a transient analysis is desired starting from other than the quiescent operating point See the IC control line for a better and more convenient way to specify transient initial conditions The optional TEMP value is the temperature at which this device is to operate and overrides the temperature specification on the OPTION control line The temperature specification is ONLY valid for level 1 2 3 and 6 MOSFETs not for level 4 or 5 BSIM devices Spice3f User s Manual 37 3 4 8 CIRCUIT ELEMENTS AND MODELS TRANSISTORS AND DIODES 3 4 8 MOSFET Models NMOS PMOS SPICE provides four MOSFET device models which differ in the formulation of the I V characteris tic The variable LEVEL specifies the model to be used LEVEL 1 gt Shichman Hodges LEVEL 2 gt MOS2 as described in 1 LEVEL 3 gt MOS3 a semi empirical model see 1 LEVEL 4 gt BSIM as described in 3 LEVEL 5 gt new BSIM BSIM2 as described in 5 LEVEL 6 gt MOS6 as described in 2 The dc characteristics of the level 1 through level 3 MOSFETs are defined by the device parameters VTO KP LAMBDA PHI and GAMMA These parameters are computed by SPICE if process parameters NSUB TOX are given but user specified values always override VTO is positive negative for enhancement mode and negative positive for depletion mode N channel P channel devices Charge storage is modeled by three constant cap
45. If this line is included SPICE computes the dc small signal value of the transfer function output input input resistance and output resistance For the first example SPICE would compute the ratio of V 5 3 to VIN the small signal input resistance at VIN and the small signal output resistance measured across nodes 5 and 3 54 User s Manual Spice3f ANALYSES AND OUTPUT CONTROL ANALYSES 4 3 9 4 3 9 TRAN Transient Analysis General form TRAN TSTEP TSTOP lt TSTART lt TMAX gt gt Examples TRAN 1NS 100NS TRAN 1NS 1000NS 500NS TRAN 10NS 1US TSTEP is the printing or plotting increment for line printer output For use with the post processor TSTEP is the suggested computing increment TSTOP is the final time and TSTART is the initial time If TSTART is omitted it is assumed to be zero The transient analysis always begins at time zero In the interval lt zero TSTART gt the circuit is analyzed to reach a steady state but no outputs are stored In the interval lt TSTART TSTOP gt the circuit is analyzed and outputs are stored TMAX is the maximum step size that SPICE uses for default the program chooses either TSTEP or TSTOP TSTART 50 0 which ever is smaller TMAX is useful when one wishes to guarantee a computing interval which is smaller than the printer increment TSTEP UIC use initial conditions is an optional keyword which indicates that the user does not want SPICE to solve for the quiesc
46. MNAME Examples 023 1 0 2 0 LOSSYMOD OCONNECT 10 5 20 5 INTERCONNECT This is a two port convolution model for single conductor lossy transmission lines N1 and N2 are the nodes at port 1 N3 and N4 are the nodes at port 2 Note that a lossy transmission line with zero loss may be more accurate than than the lossless transmission line due to implementation details Spice3f User s Manual 27 3 3 2 CIRCUIT ELEMENTS AND MODELS TRANSMISSION LINES 3 3 3 Lossy Transmission Line Model LTRA The uniform RLC RC LC RG transmission line model referred to as the LTRA model henceforth models a uniform constant parameter distributed transmission line The RC and LC cases may also be modeled using the URC and TRA models however the newer LTRA model is usually faster and more ac curate than the others The operation of the LTRA model is based on the convolution of the transmission line s impulse responses with its inputs see 8 The LTRA model takes a number of parameters some of which must be given and some of which are optional name parameter units type default example R resistance length Q unit 0 0 0 2 L inductance length henrys unit 0 0 9 13e 9 G conductance length mhos unit 0 0 0 0 C capacitance length farads unit 0 0 3 65e 12 LEN length of line no default 1 0 REL breakpoint control arbitrary unit 1 0 5 ABS breakpoint control 1 5 NOSTEPLIMIT don t limit timestep to less than line flag not set set
47. MODEL AND DEVICE PARAMETERS Diode model parameters input only d Diode model Diode model parameters input output is Saturation current tnom Parameter measurement temperature TS Ohmic resistance n Emission Coefficient tt Transit Time cjo Junction capacitance cjO null vj Junction potential m Grading coefficient eg Activation energy xti Saturation current temperature exp kf flicker noise coefficient af flicker noise exponent fc Forward bias junction fit parameter bv Reverse breakdown voltage ibv Current at reverse breakdown voltage Diode model parameters output only cond Ohmic conductance B 11 Inductor Inductors Inductor instance parameters input output inductance Inductance of inductor ic Initial current through inductor Inductor instance parameters output only flux Flux through inductor v Terminal voltage of inductor volt i Current through the inductor current p instantaneous power dissipated by the inductor Spice3f User s Manual 117 APPENDIX B MODEL AND DEVICE PARAMETERS B 12 mutual Mutual inductors mutual instance parameters input output k coefficient inductor1 inductor2 Mutual inductance null First coupled inductor Second coupled inductor B 13 Isource Independent current source Isource instance parameters input only
48. OS B 19 Mos3 Level 3 MOSfet model with Meyer capacitance model Mos3 instance parameters input only off Device initially off Mos3 instance parameters input output l Length w Width ad Drain area as Source area pd Drain perimeter ps Source perimeter nrd Drain squares nrs Source squares icvds Initial D S voltage icvgs Initial G S voltage icvbs Initial B S voltage ic Vector of D S G S B S voltages temp Instance operating temperature Mos3 instance parameters output only id Drain current cd Drain current ibd B D junction current ibs B S junction current is Source current ig Gate current ib Bulk current vgs Gate Source voltage vds Drain Source voltage vbs Bulk Source voltage vbd Bulk Drain voltage dnode Number of drain node gnode Number of gate node snode Number of source node bnode Number of bulk node dnodeprime Number of internal drain node snodeprime Number of internal source node continued Spice3f User s Manual 129 APPENDIX B MODEL AND DEVICE PARAMETERS Mos3 instance output only parameters continued von Turn on voltage vdsat Saturation drain voltage sourcevcrit Critical source voltage drainvcrit Critical drain voltage TS Source resistance sourceconductance Source conductance rd Drain resistance drainconductance Drain conductance gm Transconductance gds Drain Source conductance gmb Bulk
49. Order of the source function coeffs Coefficients for the function acreal AC real part acimag AC imaginary part i Voltage source current p Instantaneous power 138 User s Manual Spice3f
50. RA model When specified the simulator tries to condense LTRA transmission lines past history of input voltages and currents resets the absolute voltage error tolerance of the program The default value is 1 microvolt In addition the following options have the listed effect when operating in spice2 emulation mode Spice3f option option ACCT LIST NOMOD NOPAGE NODE effect effect causes accounting and run time statistics to be printed causes the summary listing of the input data to be printed suppresses the printout of the model parameters suppresses page ejects causes the printing of the node table User s Manual 47 4 1 48 ANALYSES AND OUTPUT CONTROL SIMULATOR VARIABLES OPTIONS option effect OPTS causes the option values to be printed User s Manual Spice3f ANALYSES AND OUTPUT CONTROL INITIAL CONDITIONS 4 2 4 2 INITIAL CONDITIONS 4 2 1 INODESET Specify Initial Node Voltage Guesses General form NODESET V NODNUM VAL V NODNUM VAL Examples NODESET V 12 4 5 V 4 2 23 The Nodeset line helps the program find the dc or initial transient solution by making a preliminary pass with the specified nodes held to the given voltages The restriction is then released and the iteration continues to the true solution The NODESET line may be necessary for convergence on bistable or a stable circuits In general this line should not be necessary 4 2 2 IC
51. RAMETERS BJT model input output parameters continued pe null mjc B C junction grading coefficient mc null xcjc Fraction of B C cap to internal base tr Ideal reverse transit time cjs Zero bias C S capacitance ccs Zero bias C S capacitance vjs Substrate junction built in potential ps null mjs Substrate junction grading coefficient ms null xtb Forward and reverse beta temp exp eg Energy gap for IS temp dependency xti Temp exponent for IS fc Forward bias junction fit parameter tnom Parameter measurement temperature kf Flicker Noise Coefficient af Flicker Noise Exponent BJT model parameters output only type NPN or PNP invearlyvoltf Inverse early voltage forward invearlyvoltr Inverse early voltage reverse invrollofff Inverse roll off forward invrolloffr Inverse roll off reverse collectorconduct Collector conductance emitterconduct Emitter conductance transtimevbcfact Transit time VBC factor excessphasefactor Excess phase fact Spice3f User s Manual 107 APPENDIX B MODEL AND DEVICE PARAMETERS B 4 BSIM1 Berkeley Short Channel IGFET Model BSIM1 instance parameters input only Vector of DS GS BS initial voltages BSIM1 instance parameters input output l Length w Width ad Drain area as Source area pd Drain perimeter ps Source perimeter nrd Number of squares in drain n
52. RC line with K as a proportionality constant The number of lumped segments used if not specified The URC line is made up strictly of resistor and capacitor segments unless the ISPERL parameter is for the URC line device is determined by the following formula C log Ra Sare Se LL N log K given a non zero value in which case the capacitors are replaced with reverse biased diodes with a zero bias junction capacitance equivalent to the capacitance replaced and with a saturation current of ISPERL amps per meter of transmission line and an optional series resistance equivalent to RSPERL ohms per me ter name parameter units default example area 1 K Propagation Constant 2 0 1 2 2 FMAX Maximum Frequency of interest Hz 1 0G 6 5Meg 3 RPERL Resistance per unit length Q m 1000 10 4 CPERL Capacitance per unit length F m 1 0e 15 1pF 5 ISPERL Saturation Current per unit length A m 0 6 RSPERL Diode Resistance per unit length Q im 0 30 User s Manual Spice3f CIRCUIT ELEMENTS AND MODELS TRANSISTORS AND DIODES 3 4 3 4 TRANSISTORS AND DIODES The area factor used on the diode BJT JFET and MESFET devices determines the number of equivalent parallel devices of a specified model The affected parameters are marked with an asterisk under the heading area in the model descriptions below Several geometric factors associated with the channel and the drain and source diffusions can be specified on
53. S AT DIFFERENT TEMPERATURES 1 2 Temperature appears explicitly in the value of junction potential in spice PHD for all the device models The temperature dependence is determined by NNa NT o T Liog q where k is Boltzmann s constant q is the electronic charge N is the acceptor impurity density Na is the donor impurity density N is the intrinsic carrier concentration and E is the energy gap Temperature appears explicitly in the value of surface mobility Uy or UO for the MOSFET model The temperature dependence is determined by To uo T a 3 T To The effects of temperature on resistors is modeled by the formula R T R T 1 TC T To TC T Tp where T is the circuit temperature Tp is the nominal temperature and TC and TC are the first and second order temperature coefficients Spice3f User s Manual 5 1 3 INTRODUCTION CONVERGENCE 1 3 CONVERGENCE Both dc and transient solutions are obtained by an iterative process which is terminated when both of the following conditions hold 1 The nonlinear branch currents converge to within a tolerance of 0 1 or 1 picoamp 1 0e 12 Amp whichever is larger 2 The node voltages converge to within a tolerance of 0 1 or 1 microvolt 1 0e 6 Volt whichever is larger Although the algorithm used in SPICE has been found to be very reliable in some cases it fails to converge to a solution When this
54. Source transconductance gmbs Bulk Source transconductance gbd Bulk Drain conductance gbs Bulk Source conductance cbd Bulk Drain capacitance cbs Bulk Source capacitance cgs Gate Source capacitance cgd Gate Drain capacitance cgb Gate Bulk capacitance cqgs Capacitance due to gate source charge storage cqgd Capacitance due to gate drain charge storage cqgb Capacitance due to gate bulk charge storage cqbd Capacitance due to bulk drain charge storage cqbs Capacitance due to bulk source charge storage cbd0 Zero Bias B D junction capacitance cbdsw0 Zero Bias B D sidewall capacitance cbs0 Zero Bias B S junction capacitance cbssw0 Zero Bias B S sidewall capacitance qbs Bulk Source charge storage qgs Gate Source charge storage qgd Gate Drain charge storage qgb Gate Bulk charge storage qbd Bulk Drain charge storage p Instantaneous power Mos3 model parameters input only nmos N type MOSfet model pmos P type MOSfet model 130 User s Manual Spice3f APPENDIX B MODEL AND DEVICE PARAMETERS Mos3 model parameters input output vto Threshold voltage vt0 null kp Transconductance parameter gamma Bulk threshold parameter phi Surface potential rd Drain ohmic resistance rs Source ohmic resistance cbd B D junction capacitance cbs B S junction capacitance is Bulk junction sat current pb Bulk junction potential cgso Gate source overlap cap cgdo Gate drain overlap cap cgbo Gate bulk overla
55. TO control line The key words may be followed by an optional magnitude and phase The default values of the magnitude and phase are 1 0 and 0 0 respectively Any independent source can be assigned a time dependent value for transient analysis If a source is assigned a time dependent value the time zero value is used for dc analysis There are five independent source functions pulse exponential sinusoidal piece wise linear and single frequency FM If parame ters other than source values are omitted or set to zero the default values shown are assumed TSTEP is Spice3f User s Manual 19 3 2 1 CIRCUIT ELEMENTS AND MODELS VOLTAGE AND CURRENT SOURCES the printing increment and TSTOP is the final time see the TRAN control line for explanation 3 2 1 1 Pulse General form PULSE V1 V2 TD TR TF PW PER Examples VIN 3 0 PULSE 1 1 2NS 2NS 2NS 50NS 100NS parameter default value units V1 initial value V2 pulsed value TD delay time TR rise time TF fall time PW pulse width PER period 0 0 TSTEP TSTEP TSTOP TSTOP Volts or Amps Volts or Amps seconds seconds seconds seconds seconds A single pulse so specified is described by the following table time value 0 V1 TD V1 TD TR V2 TD TR PW v2 TD TR PW TF V1 TSTOP V1 Intermediate points are determined by linear interpolation 20 User s Manual Spice3f CIRCUIT ELEMENTS AND MODELS VOLTAGE AND CURRENT SO
56. URCES _ 3 2 1 2 3 2 1 2 Sinusoidal General form SIN VO VA FREQ TD THETA Examples VIN 3 0 SIN O 1 100MEG 1NS 1E10 parameters default value units VO offset Volts or Amps VA amplitude Volts or Amps FREQ frequency 1 TSTOP Hz TD delay 0 0 seconds THETA damping factor 0 0 1 seconds The shape of the waveform is described by the following table time value 0to TD VO TD to TSTOP VO VA e t TDTHETA Sin 2 n FREQ t TD 3 2 1 3 Exponential General Form EXP V1 V2 TD1 TAU1 TD2 TAU2 Examples VIN 3 0 EXP 4 1 2NS 30NS 60NS 40NS Spice3f User s Manual 21 3 2 1 3 CIRCUIT ELEMENTS AND MODELS VOLTAGE AND CURRENT SOURCES parameter default value units V1 initial value Volts or Amps V2 pulsed value Volts or Amps TD1 rise delay time 0 0 seconds TAU rise time constant TSTEP seconds TD2 fall delay time TD1 TSTEP seconds TAU2 fall time constant TSTEP seconds The shape of the w aveform is described by the following table time value 0 to TD1 v1 t TD1 TD1 to TD2 Vi V2 Vi i e ToU t TD1 t TD2 TD2 to TSTOP VI V2 V1 e TAUL evi v2 1 e TAU 3 2 1 4 Piece Wise Linear General Form PWL T1 V1 lt T2 Examples v2 T3 V3 T4 V4 gt VCLOCK 7 5 PWL 0 7 10NS 7 TINS 3 17NS 3 18NS 7 50NS 7 Each pair of values Ti Vi specifies that the value of the source is Vi in Volts or Amps at time Ti The value
57. a resistor name must begin with the letter R and can contain one or more characters Hence R R1 RSE ROUT and R3AC2ZY are valid resistor names Details of each type of device are supplied in a following section Fields on a line are separated by one or more blanks a comma an equal sign or a left or right parenthesis extra spaces are ignored A line may be continued by entering a plus in column 1 of the following line SPICE continues reading beginning with column 2 A name field must begin with a letter A through Z and cannot contain any delimiters A number field may be an integer field 12 44 a floating point field 3 14159 either an integer or floating point number followed by an integer exponent le 14 2 65e3 or either an integer or a floating point number followed by one of the following scale factors T 107 G 10 Meg 10 K 10 mil 25 4 m 10 u or p 10 n 10 p 10 f 10 Letters immediately following a number that are not scale factors are ignored and letters immediately fol lowing a scale factor are ignored Hence 10 10V 10Volts and 10Hz all represent the same number and M MA MSec and MMhos all represent the same scale factor Note that 1000 1000 0 1000Hz 1e3 1 0e3 1KHz and 1K all represent the same number Nodes names may be arbitrary character strings The datum ground node must be named 0 Note the difference in SPICE3 where the nodes are treated as character strings
58. acitors CGSO CGDO and CGBO which represent overlap capa citances by the nonlinear thin oxide capacitance which is distributed among the gate source drain and bulk regions and by the nonlinear depletion layer capacitances for both substrate junctions divided into bottom and periphery which vary as the MJ and MJSW power of junction voltage respectively and are determined by the parameters CBD CBS CJ CJSW MJ MJSW and PB Charge storage effects are modeled by the piecewise linear voltages dependent capacitance model proposed by Meyer The thin oxide charge storage effects are treated slightly different for the LEVEL 1 model These voltage dependent capacitances are included only if TOX is specified in the input description and they are represented using Meyer s formulation There is some overlap among the parameters describing the junctions e g the reverse current can be input either as IS in A or as JS in A m Whereas the first is an absolute value the second is multiplied by AD and AS to give the reverse current of the drain and source junctions respectively This methodology has been chosen since there is no sense in relating always junction characteristics with AD and AS entered on the device line the areas can be defaulted The same idea applies also to the zero bias junction capaci tances CBD and CBS in F on one hand and CJ in F m on the other The parasitic drain and source series resistance can be expressed as either
59. al Form continue If there is a while dowhile or foreach block enclosing this statement control passes to the test or in the case of foreach the next value is taken Otherwise an error results 5 4 9 Break General Form break If there is a while dowhile or foreach block enclosing this statement control passes out of the block Otherwise an error results Of course control structures may be nested When a block is entered and the input is the termi nal the prompt becomes a number of gt s corresponding to the number of blocks the user has entered The current control structures may be examined with the debugging command cdump Spice3f User s Manual 87 5 4 9 INTERACTIVE INTERPRETER CONTROL STRUCTURES 5 5 VARIABLES The operation of both Nutmeg and Spice3 may be affected by setting variables with the set com mand In addition to the variables mentioned below the set command in Spice3 also affect the behaviour of the simulator via the options previously described under the section on OPTIONS The variables meaningful to nutmeg which may be altered by the set command are diff_abstol The absolute tolerance used by the diff command appendwrite Append to the file when a write command is issued if one already ex ists colorN These variables determine the colors used if X is being run on a color display N may be between 0 and 15 Color 0 is the background color 1 is the grid and text color and colo
60. al V 0 75 34 MJS substrate junction exponential factor 0 0 5 35 XTB forward and reverse beta temperature exponent 0 36 EG energy gap for temperature effect on IS eV 1 11 37 XTI temperature exponent for effect on IS 3 38 KF flicker noise coefficient 0 39 AF flicker noise exponent 1 40 FC coefficient for forward bias depletion capacitance formula 0 5 41 TNOM Parameter measurement temperature C 27 50 3 4 5 Junction Field Effect Transistors JFETs General form JXXXXXXX ND NG NS MNAME lt AREA gt lt OFF gt lt IC VDS VGS gt lt TEMP T gt Examples J1 7 2 3 JM1 OFF ND NG and NS are the drain gate and source nodes respectively MNAME is the model name AREA is the area factor and OFF indicates an optional initial condition on the device for dc analysis If the area factor is omitted a value of 1 0 is assumed The optional initial condition specification using IC VDS VGS is intended for use with the UIC option on the TRAN control line when a transient analysis is desired starting from other than the quiescent operating point See the IC control line for a better way to set initial conditions The optional TEMP value is the temperature at which this device is to operate and overrides the temperature specification on the OPTION control line Spice3f User s Manual 35 3 4 6 CIRCUIT ELEMENTS AND MODELS TRANSISTORS AND DIODES 3 4 6 JFET Models NJE PJF The JFET model is derived from th
61. ance gain control Controlling voltage source CCVS instance parameters output only pos_node Positive node of source neg_node Negative node of source i CCVS output current v CCVS output voltage p CCVS power B 9 CSwitch Current controlled ideal switch CSwitch instance parameters input only on off Initially closed Initially open Spice3f User s Manual 115 APPENDIX B MODEL AND DEVICE PARAMETERS CSwitch instance parameters input output control Name of controlling source CSwitch instance parameters output only pos_node Positive node of switch neg_node Negative node of switch i Switch current p Instantaneous power CSwitch model parameters input output csw Current controlled switch model it Threshold current ih Hysterisis current ron Closed resistance roff Open resistance CSwitch model parameters output only gon Closed conductance goff Open conductance B 10 Diode Junction Diode model Diode instance parameters input output off Initially off temp Instance temperature ic Initial device voltage area Area factor Diode instance parameters output only vd Diode voltage id Diode current c Diode current gd Diode conductance cd Diode capacitance charge Diode capacitor charge capcur Diode capacitor current p Diode power 116 User s Manual Spice3f APPENDIX B
62. arameters input only nmos N type MOSfet model pmos P type MOSfet model Spice3f User s Manual 127 APPENDIX B MODEL AND DEVICE PARAMETERS Mos2 model parameters input output vto Threshold voltage vtO null kp Transconductance parameter gamma Bulk threshold parameter phi Surface potential lambda Channel length modulation rd Drain ohmic resistance TS Source ohmic resistance cbd B D junction capacitance cbs B S junction capacitance is Bulk junction sat current pb Bulk junction potential cgso Gate source overlap cap cgdo Gate drain overlap cap cgbo Gate bulk overlap cap rsh Sheet resistance cj Bottom junction cap per area mj Bottom grading coefficient cjsw Side junction cap per area mjsw Side grading coefficient js Bulk jct sat current density tox Oxide thickness ld Lateral diffusion u0 Surface mobility uo null fc Forward bias jct fit parm nsub Substrate doping tpg Gate type nss Surface state density delta Width effect on threshold uexp Crit field exp for mob deg ucrit Crit field for mob degradation vmax Maximum carrier drift velocity xj Junction depth neff Total channel charge coeff nfs Fast surface state density tnom Parameter measurement temperature kf Flicker noise coefficient af Flicker noise exponent 128 User s Manual Spice3f APPENDIX B MODEL AND DEVICE PARAMETERS Mos2 model parameters output only type N channel or P channel M
63. ation system that provides all the parameters thus there are no defaults for the parameters and leav ing one out is considered an error For an example set of parameters and the format of a process file see the SPICE2 implementation notes 3 For more information on BSIM2 see reference 5 SPICE BSIM level 4 parameters name parameter units I w VFB flat band voltage V PHI surface inversion potential V 7 K1 body effect coefficient vie s K2 drain source depletion charge sharing coefficient i ETA zero bias drain induced barrier lowering coefficient MUZ zero bias mobility cm V s DL shortening of channel um DW narrowing of channel um U0 zero bias transverse field mobility degradation coefficient vi U1 zero bias velocity saturation coefficient um V i X2MZ sens of mobility to substrate bias at va 0 cm7 V7 s_ X2E sens of drain induced barrier lowering effect to substrate bias N X3E sens of drain induced barrier lowering effect to drain bias at Vjy Vag V7 X2U0 sens of transverse field mobility degradation effect to substrate bias y x X2U1 sens of velocity saturation effect to substrate bias umy 7 Spice3f User s Manual 41 3 4 8 name MUS X2MS X3MS X3U1 TOX TEMP VDD CGDO CGSO CGBO XPART NO NB ND RSH JS PB MJ PBSW MJSW CJ CJSW WDF DELL CIRCUIT ELEMENTS AND MODELS TRANSISTORS AND DIODES parameter mobility at zero substrate bias and at Vy Vaq sens of mobility to substrate bias at
64. ative Node 104 User s Manual Spice3f APPENDIX B MODEL AND DEVICE PARAMETERS B 3 BJT Bipolar Junction Transistor BJT instance parameters input only Initial condition vector BJT instance parameters input output off Device initially off icvbe Initial B E voltage icvce Initial C E voltage area Area factor temp instance temperature BJT instance parameters output only colnode Number of collector node basenode Number of base node emitnode Number of emitter node substnode Number of substrate node colprimenode Internal collector node baseprimenode Internal base node emitprimenode Internal emitter node ic Current at collector node ib Current at base node ie Emitter current is Substrate current vbe B E voltage vbe B C voltage gm Small signal transconductance gpi Small signal input conductance pi gmu Small signal conductance mu gx Conductance from base to internal base go Small signal output conductance geqcb d Ibe d Vbc gecs Internal C S cap equiv cond geqbx Internal C B base cap equiv cond cpi Internal base to emitter capactance cmu Internal base to collector capactiance cbx Base to collector capacitance ccs Collector to substrate capacitance cqbe Cap due to charge storage in B E jct cqbc Cap due to charge storage in B C jct cqcs Cap due to charge storage in C S jct cqbx Cap due to charge storage in B X jct continued Spice3f Us
65. ch are positive numbers name parameter units default example area 1 IS saturation current A 1 0e 14 1 0e 14 2 RS ohmic resistance Q 0 10 3 N emission coefficient 1 1 0 4 TT transit time sec 0 0 1ns 5 CJO zero bias junction capacitance F 0 2pF 6 VJ junction potential V 1 0 6 7 M grading coefficient 0 5 0 5 8 EG activation energy eV 1 11 1 11 Si 0 69 Sbd 0 67 Ge 9 XTI saturation current temp exp 3 0 3 0 jn 2 0 Sbd 10 KF flicker noise coefficient 0 11 AF flicker noise exponent 1 12 FC coefficient for forward bias 0 5 depletion capacitance formula 13 BV reverse breakdown voltage V infinite 40 0 14 IBV current at breakdown voltage A 1 0e 3 15 TNOM parameter measurement temperature C 27 50 32 User s Manual Spice3f CIRCUIT ELEMENTS AND MODELS TRANSISTORS AND DIODES 3 4 3 3 4 3 Bipolar Junction Transistors BJTs General form OXXXXXXX NC NB NE lt NS gt MNAME lt AREA gt lt OFF gt lt IC VBE VCE gt lt TEMP T gt Examples Q23 10 24 13 QMOD IC 0 6 5 0 Q50A 11 26 4 20 MODI NC NB and NE are the collector base and emitter nodes respectively NS is the optional sub strate node If unspecified ground is used MNAME is the model name AREA is the area factor and OFF indicates an optional initial condition on the device for the dc analysis If the area factor is omitted a value of 1 0 is assumed The optional initial condition specification using IC VBE VCE is int
66. ck which forces BJTs to have 4 nodes for the purposes of subcircuit expansion at least The name param notation might not work with trace iplot etc yet The first line of a command file except for the spiceinit file should be a comment otherwise SPICE may create an empty circuit Files specified on the command line are read before spiceinit is read 94 User s Manual Spice3f INTERACTIVE INTERPRETER BUGS 5 7 Spice3f User s Manual 95 96 User s Manual Spice3f 6 BIBLIOGRAPHY 1 10 11 A Vladimirescu and S Liu The Simulation of MOS Integrated Circuits Using SPICE2 ERL Memo No ERL M80 7 Electronics Research Laboratory University of California Berkeley October 1980 T Sakurai and A R Newton A Simple MOSFET Model for Circuit Analysis and its application to CMOS gate delay analysis and series connected MOSFET Structure ERL Memo No ERL M90 19 Electronics Research Laboratory University of California Berkeley March 1990 B J Sheu D L Scharfetter and P K Ko SPICE2 Implementation of BSIM ERL Memo No ERL M85 42 Electronics Research Laboratory University of California Berkeley May 1985 J R Pierret A MOS Parameter Extraction Program for the BSIM Model ERL Memo Nos ERL M84 99 and M84 100 Electronics Research Laboratory University of California Berkeley November 1984 Min Chie Jeng Design and Modeling of Deep Submicrometer MOSFETSs ERL Memo Nos ERL M90 90 Electronics
67. control line F2 is kept fixed at a single frequency as F1 sweeps the value at which it is kept fixed is equal to FLOVERF1 times FSTART Each independent source in the circuit may potentially have two superimposed sinusoidal inputs for distortion at the frequencies Fl and F2 The magnitude and phase of the F1 component are specified by the arguments of the DISTOF1 keyword in the source s input line see the description of independent sources the magnitude and phase of the F2 component are speci fied by the arguments of the DISTOF2 keyword The analysis produces plots of all node voltages branch currents at the intermodulation product frequencies Fl F2 F1 F2 and 2 F1 F2 vs the swept fre quency F1 The IM product of interest may be selected using the setplot command and displayed with the print and plot commands It is to be noted as in the harmonic analysis case the results are the actual AC Spice3f User s Manual 51 4 3 3 ANALYSES AND OUTPUT CONTROL ANALYSES voltages and currents at the intermodulation frequencies and need to be normalized with respect to AC values to obtain the IM parameters If the DISTOF1 or DISTOF2 keywords are missing from the description of an independent source then that source is assumed to have no input at the corresponding frequency The default values of the magnitude and phase are 1 0 and 0 0 respectively The phase should be specified in degrees It should be carefully noted that the nu
68. currently active transient analysis The currently loaded input file must include a transient analysis a tran command may be run interactively before the last reset alternately and the current plot must be from this transient analysis This command is needed be cause Spice3 doesn t output the results from a transient analysis in the same manner that Spice did 5 3 24 Listing Print a listing of the current circuit General Form listing logical physical deck expand If the logical argument is given the listing is with all continuation lines collapsed into one line and if the physical argument is given the lines are printed out as they were found in the file The de fault is logical A deck listing is just like the physical listing except without the line numbers it re creates the input file verbatim except that it does not preserve case If the word expand is present the circuit is printed with all subcircuits expanded 5 3 25 Load Load rawfile data General Form load filename Loads either binary or ascii format rawfile data from the files named The default filename is rawspice raw or the argument to the r flag if there was one 5 3 26 Op Perform an operating point analysis General Form op Do an operating point analysis See the previous sections of this manual for more details Spice3f User s Manual 71 5 3 26 INTERACTIVE INTERPRETER COMMANDS 5 3 27 Plot Plot values on the display
69. d a value of 1 0 is assumed The optional initial condition specification using IC VDS VGS is intended for use with the UIC option on the TRAN control line when a transient analysis is desired starting from other than the quiescent operating point See the IC control line for a better way to set initial conditions 42 User s Manual Spice3f CIRCUIT ELEMENTS AND MODELS TRANSISTORS AND DIODES 3 4 9 3 4 9 MESFETs General form ZXXXXXXX ND NG NS MNAME lt AREA gt lt OFF gt lt IC VDS VGS gt Examples Zl 7 2 3 ZM1 OFF 3 4 10 MESFET Models NMF PMF The MESFET model is derived from the GaAs FET model of Statz et al as described in 11 The dc characteristics are defined by the parameters VTO B and BETA which determine the variation of drain current with gate voltage ALPHA which determines saturation voltage and LAMBDA which determines the output conductance The formula are given by 3 V V Vas j PO NE gaa A A Va prUevne 1 b V Vp 3 a VaV a P Ve Vo A Vag Ovo 1 0 V Vp a Two ohmic resistances RD and RS are included Charge storage is modeled by total gate charge as a function of gate drain and gate source voltages and is defined by the parameters CGS CGD and PB name parameter units default example area 1 VTO pinch off voltage V 2 0 2 0 2 BETA transconductance parameter A V 1 0e 4 1 0e 3 7 3 B doping tail extending parameter 1 V 0 3 0 3 4 ALPHA sat
70. d but may be used for setting many breakpoints COMPACTREL may also be experimented with when the option TRY TOCOMPACT is specified in a OPTIONS card The legal range is between 0 and 1 Larger values usually decrease the accuracy of the simulation but in some cases improve speed If TRYTOCOMPACT is not specified on a OPTIONS card history compaction is not attempted and accuracy is high NOCONTROL TRUNCDONTCUT and NOS TEPLIMIT also tend to increase speed at the expense of accuracy 3 3 4 Uniform Distributed RC Lines Lossy General form UXXXXXXX N1 N2 N3 MNAME L LEN lt N LUMPS gt Examples U1 1 2 0 URCMOD L 50U URC2 1 12 2 UMODL 1 1MIL N 6 N1 and N2 are the two element nodes the RC line connects while N3 is the node to which the capa citances are connected MNAME is the model name LEN is the length of the RC line in meters LUMPS if specified is the number of lumped segments to use in modeling the RC line see the model description for the action taken if this parameter is omitted Spice3f User s Manual 29 3 3 5 CIRCUIT ELEMENTS AND MODELS TRANSMISSION LINES 3 3 5 Uniform Distributed RC Model URC The URC model is derived from a model proposed by L Gertzberrg in 1974 The model is accom plished by a subcircuit type expansion of the URC line into a network of lumped RC segments with inter nally generated nodes The RC segments are in a geometric progression increasing toward the middle of the U
71. d together and presented though this could presumably be done as a postprocessing step Currently the interested user should keep track of the mix frequencies himself or herself and add the distortions at coinciding mix frequencies together should it be necessary 4 3 4 NOISE Noise Analysis General form NOISE V OUTPUT lt REF gt SRC DEC LIN OCT PTS FSTART FSTOP lt PTS_PER_SUMMARY gt Examples NOISE V 5 VIN DEC 10 1kHZ 100Mhz NOISE V 5 3 V1 OCT 8 1 0 1 0e6 1 The Noise line does a noise analysis of the circuit OUTPUT is the node at which the total output noise is desired if REF is specified then the noise voltage V OUTPUT V REF is calculated By default REF is assumed to be ground SRC is the name of an independent source to which input noise is referred PTS FSTART and FSTOP are AC type parameters that specify the frequency range over which plots are desired PTS_PER_SUMMARY is an optional integer if specified the noise contributions of each noise generator is produced every PTS_PER_SUMMARY frequency points 52 User s Manual Spice3f ANALYSES AND OUTPUT CONTROL ANALYSES 4 3 4 The NOISE control line produces two plots one for the Noise Spectral Density curves and one for the total Integrated Noise over the specified frequency range All noise voltages currents are in squared units V Hz and A Hz for spectral density V and A for integrated noise 4 3 5 OP Operatin
72. different vectors in the two plots or any values in the vectors differ significantly the difference is reported The variable diff_abstol diff_reltol and diff_vntol are used to determine a significant difference 5 3 13 Display List known vectors and types General Form display varname Prints a summary of currently defined vectors or of the names specified The vectors are sorted by name unless the variable nosort is set The information given is the name of the vector the length the type of the vector and whether it is real or complex data Additionally one vector is labeled scale When a command such as plot is given without a vs argument this scale is used for the X axis It is always the first vector in a rawfile or the first vector defined in a new plot If you undefine the scale i e Jet TIME one of the remaining vectors becomes the new scale which is undeter mined 5 3 14 Echo Print text General Form echo text Echos the given text to the screen 68 User s Manual Spice3f INTERACTIVE INTERPRETER COMMANDS 5 3 15 5 3 15 Edit Edit the current circuit General Form edit file Print the current Spice3 input file into a file call up the editor on that file and allow the user to modify it and then read it back in replacing the original file If a filename is given then edit that file and load it making the circuit the current one 5 3 16 Fourier Perform a fourier tran
73. e vbs Bulk Source voltage vbd Bulk Drain voltage dnode Number of drain node gnode Number of gate node snode Number of source node bnode Number of bulk node dnodeprime Number of internal drain node snodeprime Number of internal source node von vdsat Saturation drain voltage sourcevcrit Critical source voltage drainvcrit Critical drain voltage continued 126 User s Manual Spice3f APPENDIX B MODEL AND DEVICE PARAMETERS Mos 2 instance output only parameters continued TS Source resistance sourceconductance Source conductance rd Drain resistance drainconductance Drain conductance gm Transconductance gds Drain Source conductance gmb Bulk Source transconductance gmbs gbd Bulk Drain conductance gbs Bulk Source conductance cbd Bulk Drain capacitance cbs Bulk Source capacitance cgs Gate Source capacitance cgd Gate Drain capacitance cgb Gate Bulk capacitance cbd0 Zero Bias B D junction capacitance cbdsw0 cbs0 Zero Bias B S junction capacitance cbssw0 cqgs Capacitance due to gate source charge storage cqgd Capacitance due to gate drain charge storage cqgb Capacitance due to gate bulk charge storage cqbd Capacitance due to bulk drain charge storage cqbs Capacitance due to bulk source charge storage qgs Gate Source charge storage qgd Gate Drain charge storage qgb Gate Bulk charge storage qbd Bulk Drain charge storage qbs Bulk Source charge storage p Instantaneous power Mos2 model p
74. e 10 16 RSH drain and source diffusion sheet resistance Q 0 0 10 0 17 CJ zero bias bulk junction bottom cap per sq meter of junction area F m 0 0 2 0e 4 18 MJ bulk junction bottom grading coeff 0 5 0 5 19 CJSW zero bias bulk junction sidewall cap per meter of junction perimeter F m 0 0 1 0e 9 20 MJSW bulk junction sidewall grading coeff 0 50 level1 0 33 level2 3 21 JS bulk junction saturation current per sq meter of junction area A m 1 0e 8 22 TOX oxide thickness meter 1 0e 7 1 0e 7 23 NSUB substrate doping I em 0 0 4 0e15 24 NSS surface state density lem 0 0 1 0e10 25 NES fast surface state density l m 0 0 1 0e10 continued Spice3f User s Manual 39 3 4 8 40 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 CIRCUIT ELEMENTS AND MODELS TRANSISTORS AND DIODES name TPG XJ LD UO UCRIT UEXP UTRA VMAX NEFF AF FC DELTA THETA ETA KAPPA TNOM parameter type of gate material 1 opp to substrate 1 same as substrate 0 Al gate metallurgical junction depth lateral diffusion surface mobility critical field for mobility degradation MOS only critical field exponent in mobility degradation MOS2 only transverse field coeff mobility deleted for MOS2 maximum drift velocity of carriers total channel charge fixed and mobile coefficient MOS2 only flicker noise coefficient flicker noise exponent coefficient for forward bias de
75. e FET model of Shichman and Hodges The dc characteristics are defined by the parameters VTO and BETA which determine the variation of drain current with gate vol tage LAMBDA which determines the output conductance and IS the saturation current of the two gate junctions Two ohmic resistances RD and RS are included Charge storage is modeled by nonlinear de pletion layer capacitances for both gate junctions which vary as the 1 2 power of junction voltage and are defined by the parameters CGS CGD and PB Note that in Spice3f and later a fitting parameter B has been added For details see 9 name VTO 2 BETA 3 LAMBDA 4 RD 5 RS 6 CGS 7 CGD 8 PB 9 IS 10 B 11 KF 12 AF 13 FC 14 TNOM 36 parameter threshold voltage Vro transconductance parameter B channel length modulation parameter A drain ohmic resistance source ohmic resistance zero bias G S junction capacitance C zero bias G D junction capacitance Cys gate junction potential gate junction saturation current Is doping tail parameter flicker noise coefficient flicker noise exponent coefficient for forward bias depletion capacitance formula parameter measurement temperature User s Manual units Vv A V C default 2 0 1 0e 4 Oe 14 or OF Fr OO Co Co Oo example 2 0 1 0e 3 1 0e 4 100 100 SpF lpF 0 6 1 0e 14 1 1 50 area Spice3f CIRCUIT ELEMENTS AND MODELS TRANSISTORS AND DIODES 3 4 7
76. e of k2 wk2 Width dependence of k2 etaO VDS dependence of threshold voltage at VDD 0 letaO Length dependence of eta0 weta0 Width dependence of etaO etab VBS dependence of eta letab Length dependence of etab wetab Width dependence of etab dl Channel length reduction in um dw Channel width reduction in um muO Low field mobility at VDS 0 VGS VTH mu0b VBS dependence of low field mobility Imu0b Length dependence of mu0b wmu0b Width dependence of mu0b mus0 Mobility at VDS VDD VGS VTH ImusO Length dependence of mus0 wmus0 Width dependence of mus musb VBS dependence of mus Imusb Length dependence of musb wmusb Width dependence of musb mu20 VDS dependence of mu in tanh term Ilmu20 Length dependence of mu20 wmu20 Width dependence of mu20 mu2b VBS dependence of mu2 Imu2b Length dependence of mu2b wmu2b Width dependence of mu2b mu2g VGS dependence of mu2 continued Spice3f User s Manual 111 APPENDIX B MODEL AND DEVICE PARAMETERS BSIM2 model input output parameters continued Imu2g Length dependence of mu2g wmu2g Width dependence of mu2g mu30 VDS dependence of mu in linear term Imu30 Length dependence of mu30 wmu30 Width dependence of mu30 mu3b VBS dependence of mu3 Imu3b Length dependence of mu3b wmu3b Width dependence of mu3b mu3g VGS dependence of mu3 Imu3g Length dependence of mu3g wmu3g Width dependence of mu3g mu40 VDS dependence of mu in linear term Imu40 Length dependence
77. e specified input source This is done for every frequency point in a specified range the calculated value of the noise corresponds to the spectral density of the circuit variable viewed as a stationary gaussian stochastic process After calculating the spectral densities noise analysis integrates these values over the specified fre quency range to arrive at the total noise voltage current over this frequency range This calculated value corresponds to the variance of the circuit variable viewed as a stationary gaussian process Spice3f User s Manual 3 1 2 INTRODUCTION ANALYSIS AT DIFFERENT TEMPERATURES 1 2 ANALYSIS AT DIFFERENT TEMPERATURES All input data for SPICE is assumed to have been measured at a nominal temperature of 27 C which can be changed by use of the TNOM parameter on the OPTION control line This value can further be overridden for any device which models temperature effects by specifying the TNOM parameter on the model itself The circuit simulation is performed at a temperature of 27 C unless overridden by a TEMP parameter on the OPTION control line Individual instances may further override the circuit temperature through the specification of a TEMP parameter on the instance Temperature dependent support is provided for resistors diodes JFETs BJTs and level 1 2 and 3 MOSFETs BSIM levels 4 and 5 MOSFETs have an alternate temperature dependency scheme which adjusts all of the model parameters before in
78. en defining aliases like alias pdb plot db ate 2 you must be careful to quote the argument list substitutions in this manner If you quote the whole ar gument it might not work properly In a user defined function the arguments cannot be part of a name that uses the plot vec syntax For example define check v 1 cos tranl v 1 does not work If you type plot all all or otherwise use a wildcard reference for one plot twice in a command the effect is unpredictable The asciiplot command doesn t deal with log scales or the delta keywords Often the names of terminals recognized by MFB are different from those in etc termcap Thus you may have to reset your terminal type with the command set term termname where termname is the name in the mfbcap file The hardcopy command is useless on VMS and other systems without the plot command unless the user has a program that understands plot 5 format Spice3 recognizes all the notations used in SPICE2 plot cards and translates vp 1 into ph v 1 and so forth However if there are spaces in these names it won t work Hence v 1 2 and 5 5 aren t recognized BJTs can have either 3 or 4 nodes which makes it difficult for the subcircuit expansion routines to decide what to rename If the fourth parameter has been declared as a model name then it is assumed that there are 3 nodes otherwise it is considered a node To disable this you can set the variable nobjtha
79. ended for use with the UIC option on the TRAN control line when a transient analysis is desired starting from other than the quiescent operating point See the IC control line description for a better way to set tran sient initial conditions The optional TEMP value is the temperature at which this device is to operate and overrides the temperature specification on the OPTION control line 3 4 4 BJT Models NPN PNP The bipolar junction transistor model in SPICE is an adaptation of the integral charge control model of Gummel and Poon This modified Gummel Poon model extends the original model to include several effects at high bias levels The model automatically simplifies to the simpler Ebers Moll model when cer tain parameters are not specified The parameter names used in the modified Gummel Poon model have been chosen to be more easily understood by the program user and to reflect better both physical and cir cuit design thinking The dc model is defined by the parameters IS BF NF ISE IKF and NE which determine the for ward current gain characteristics IS BR NR ISC IKR and NC which determine the reverse current gain characteristics and VAF and VAR which determine the output conductance for forward and reverse regions Three ohmic resistances RB RC and RE are included where RB can be high current dependent Base charge storage is modeled by forward and reverse transit times TF and TR the forward transit time TF bein
80. enote for instance Thus some contrived examples of expressions are cos TIME db v 3 sin cos log 1 2 3 4 5 67 8 9 10 TIME rnd v 9 15 cos vin branch 7 9e5 8 not ac3 FREQ 32 amp tranl TIME 10 gt 3 Vector names in spice may have a name such as name param where name is either the name of a device instance or model This denotes the value of the param parameter of the device or model See Appendix B for details of what parameters are available The value is a vector of length 1 This function is also available with the show command and is available with variables for convenience for command scripts 62 User s Manual Spice3f INTERACTIVE INTERPRETER EXPRESSIONS FUNCTIONS AND CONSTANTS 5 1 There are a number of pre defined constants in nutmeg They are pi T 3 14159 e The base of natural logarithms 2 71828 c The speed of light 299 792 500 m sec i The square root of 1 kelvin Absolute 0 in Centigrade 273 15 C echarge The charge on an electron 1 6021918e 19 C boltz Boltzman s constant 1 3806226e 23 planck Planck s constant h 6 626200e 34 These are all in MKS units If you have another variable with a name that conflicts with one of these then it takes precedence Spice3f User s Manual 63 5 2 INTERACTIVE INTERPRETER COMMAND INTERPRETATION 5 2 COMMAND INTERPRETATION If a word is typed as a command and there is no built in command with that name
81. ent operating point before beginning the transient analysis If this keyword is specified SPICE uses the values specified using IC on the various elements as the initial transient con dition and proceeds with the analysis If the IC control line has been specified then the node voltages on the IC line are used to compute the initial conditions for the devices Look at the description on the IC control line for its interpretation when UIC is not specified Spice3f User s Manual 55 4 4 ANALYSES AND OUTPUT CONTROL BATCH OUTPUT 4 4 BATCH OUTPUT 4 4 1 SAVE Lines General form SAVE vector vector vector Examples SAVE i vin input output SAVE ml1 id The vectors listed on the SAVE line are recorded in the rawfile for use later with spice3 or nutmeg nutmeg is just the data analysis half of spice3 without the ability to simulate The standard vector names are accepted If no SAVE line is given then the default set of vectors are saved node voltages and vol tage source branch currents If SAVE lines are given only those vectors specified are saved For more discussion on internal device data see Appendix B See also the section on the interactive command interpretor for information on how to use the rawfile 4 4 2 PRINT Lines General form PRINT PRTYPE OV1 lt OV2 OV8 gt Examples PRINT TRAN V 4 I VIN PRINT DC V 2 I VSRC V 23 17 PRINT AC VM 4 2 VR 7 VP 8 3 The Pri
82. er s Manual 105 APPENDIX B MODEL AND DEVICE PARAMETERS BJT instance output only parameters continued cexbc Total Capacitance in B X junction qbe Charge storage B E junction qbc Charge storage B C junction qcs Charge storage C S junction qbx Charge storage B X junction p Power dissipation BJT model parameters input output npn NPN type device pnp PNP type device is Saturation Current bf Ideal forward beta nf Forward emission coefficient vaf Forward Early voltage va null ikf Forward beta roll off corner current ik null ise B E leakage saturation current ne B E leakage emission coefficient br Ideal reverse beta nr Reverse emission coefficient var Reverse Early voltage vb null ikr reverse beta roll off corner current isc B C leakage saturation current nc B C leakage emission coefficient tb Zero bias base resistance irb Current for base resistance rb rbm 2 rbm Minimum base resistance re Emitter resistance rc Collector resistance cje Zero bias B E depletion capacitance vje B E built in potential pe null mje B E junction grading coefficient me null tf Ideal forward transit time xtf Coefficient for bias dependence of TF vtf Voltage giving VBC dependence of TF itf High current dependence of TF ptf Excess phase cjc Zero bias B C depletion capacitance vjc B C built in potential continued 106 User s Manual Spice3f APPENDIX B MODEL AND DEVICE PA
83. ese command files almost like builtin commands 64 User s Manual Spice3f INTERACTIVE INTERPRETER COMMANDS 5 3 5 3 COMMANDS 5 3 1 Ac Perform an AC small signal frequency response analysis General Form ac DEC OCT LIN N Fstart Fstop Do an ac analysis See the previous sections of this manual for more details 5 3 2 Alias Create an alias for a command General Form alias word text Causes word to be aliased to text History substitutions may be used as in C shell aliases 5 3 3 Alter Change a device or model parameter General Form alter device value alter device parameter value parameter value Alter changes the value for a device or a specified parameter of a device or model The first form is used by simple devices which have one principal value resistors capacitors etc where the second form is for more complex devices bjt s etc Model parameters can be changed with the second form if the name contains a For specifying vectors as values start the vector with followed by the values in the vector and end with Be sure to place a space between each of the values and before and after the and e Spice3f User s Manual 65 5 3 4 INTERACTIVE INTERPRETER COMMANDS 5 3 4 Asciiplot Plot values using old style character plots General Form asciiplot plotargs Produce a line printer plot of the vectors The plot is sent to the standard output s
84. ferent from the one you are running Spice3 or Nutmeg on DISPLAY should be of the form machine 0 0 See the appropriate documentation on the X Window Sytem for more details Command Synopsis spice n t term r rawfile b i input file nutmeg n t term datafile Options are Don t try to load the default data file rawspice raw if no other files are given Nutmeg only n or N Don t try to source the file spiceinit upon startup Normally spice and nutmeg try to find the file in the current directory and if it is not found then in the user s home directory t term or T term The program is being run on a terminal with mfb name term b or B Run in batch mode Spice3 reads the default input source e g keyboard or reads the given input file and performs the analyses specified output is either Spice2 like line printer plots ascii plots or a spice rawfile See the following section for details Note that if the input source is not a termi nal e g using the IO redirection notation of lt Spice3 defaults to batch mode i overrides This option is valid for Spice3 only s or S Run in server mode This is like batch mode except that a temporary rawfile is used and then writ ten to the standard output preceded by a line with a single after the simulation is done This mode is used by the spice daemon This option is valid for Spice3 only S
85. ficient pbsw Source drain side junction capacitance built in potential mjsw Source drain side junction capacitance grading coefficient cj Source drain bottom junction capacitance per unit area cjsw Source drain side junction capacitance per unit area wdf Default width of source drain diffusion in um dell Length reduction of source drain diffusion B 6 Capacitor Fixed capacitor Capacitor instance parameters input output capacitance Device capacitance ic Initial capacitor voltage w Device width l Device length Capacitor instance parameters output only i Device current p Instantaneous device power Capacitor model parameters input only c Capacitor model Capacitor model parameters input output cj Bottom Capacitance per area cjsw Sidewall capacitance per meter defw Default width narrow width correction factor 114 User s Manual Spice3f APPENDIX B MODEL AND DEVICE PARAMETERS B 7 CCCS Current controlled current source CCCS instance parameters input output gain Gain of source control Name of controlling source CCCS instance parameters output only neg_node Negative node of source pos_node Positive node of source i CCCS output current v CCCS voltage at output p CCCS power B 8 CCVS Linear current controlled current source CCVS instance parameters input output gain Transresist
86. from different analyses 5 1 EXPRESSIONS FUNCTIONS AND CONSTANTS Spice and Nutmeg data is in the form of vectors time voltage etc Each vector has a type and vec tors can be operated on and combined algebraicly in ways consistent with their types Vectors are nor mally created when a data file is read in see the load command below and when the initial datafile is loaded They can also be created with the let command An expression is an algebraic formula involving vectors and scalars a scalar is a vector of length 1 and the following operations ff Q is the modulo operator and the comma operator has two meanings if it is present in the argument list of a user definable function it serves to separate the arguments Otherwise the term x y is synonymous with x j y 60 User s Manual Spice3f INTERACTIVE INTERPRETER EXPRESSIONS FUNCTIONS AND CONSTANTS 5 1 Also available are the logical operations amp and or not and the relational operations lt gt gt lt and lt gt not equal If used in an algebraic expression they work like they would in C producing values of O or 1 The relational operators have the following synonyms gt gt It lt ge gt le lt ne lt gt eq and amp or not These are useful when lt and gt might be confused with IO redirection which is almost always The following functions are available mag vector The magni
87. g Point Analysis General form lt OP The inclusion of this line in an input file directs SPICE to determine the dc operating point of the cir cuit with inductors shorted and capacitors opened Note a DC analysis is automatically performed prior to a transient analysis to determine the transient initial conditions and prior to an AC small signal Noise and Pole Zero analysis to determine the linearized small signal models for nonlinear devices see the KEEPO PINFO variable above 4 3 6 PZ Pole Zero Analysis General form PZ NODE1 NODE2 NODE3 NODE4 CUR PZ NODE1 NODE2 NODE3 NODE4 CU PZ NODE1 NODE2 NODE3 NODE4 CUR PZ NODE1 NODE2 NODE3 NODE4 VOL PZ NODE1 NODE2 NODE3 NODE4 VOL PZ NODE1 NODE2 NODE3 NODE4 VOL ve UN UUN T HONHO N UR POL U N mor ewo e U1 W FOO aQa lt a O E N Led W UR PZ CUR stands for a transfer function of the type output voltage input current while VOL stands for a transfer function of the type output voltage input voltage POL stands for pole analysis only ZER for zero analysis only and PZ for both This feature is provided mainly because if there is a nonconvergence in finding poles or zeros then at least the other can be found Finally NODE1 and NODE2 are the two input nodes and NODE3 and NODE4 are the two output nodes Thus there is complete freedom regarding the output and input ports and the type of transfer f
88. g bias dependent if desired and nonlinear depletion layer capacitances which are determined by CJE VJE and MJE for the B E junction CJC VJC and MJC for the B C junction and CJS VJS and MJS for the C S Collector Substrate junction The temperature dependence of the saturation current IS is determined by the energy gap EG and the saturation current temperature exponent XTI Additionally base current temperature dependence is modeled by the beta temperature exponent XTB in the new model The values specified are assumed to have been measured at the temperature TNOM which can be speci fied on the OPTIONS control line or overridden by a specification on the MODEL line Spice3f User s Manual 33 3 4 4 CIRCUIT ELEMENTS AND MODELS TRANSISTORS AND DIODES The BJT parameters used in the modified Gummel Poon model are listed below The parameter names used in earlier versions of SPICE2 are still accepted 34 nan BW N 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 Modified Gummel Poon BJT Parameters name IS BF NF VAF IKF ISE NE BR NR VAR IKR ISC NC RB IRB RBM RE RC CJE VJE MJE TF XTF VTF ITF PTF CJC VIC parameter transport saturation current ideal maximum forward beta forward current emission coefficient forward Early voltage corner for forward beta high current roll off B E leakage saturation current B E leakage emission coefficient ideal
89. gt amp gt gt amp and lt have the same effects as in the C shell 92 User s Manual Spice3f INTERACTIVE INTERPRETER MISCELLANEOUS 5 6 You may type multiple commands on one line separated by semicolons If you want to use a different mfbcap file than the default usually cad lib mfbcap you have to set the environment variable SPICE_MFBCAP before you start nutmeg or spice The m option and the mfbeap variable no longer work If X is being used the cursor may be positioned at any point on the screen when the window is up and characters typed at the keyboard are added to the window at that point The window may then be sent to a printer using the xpr 1 program Nutmeg can be run under VAX VMS as well as several other operating systems Some features like command completion expansion of and backquote substitution the shell command and so forth do not work On some systems you have to respond to the more prompt during plot with a carriage return instead of any key as you can do on UNIX Spice3f User s Manual 93 5 7 INTERACTIVE INTERPRETER BUGS 5 7 BUGS The label entry facilities are primitive You must be careful to type slowly when entering labels nutmeg checks for input once every second and can get confused if characters arrive faster If you redefine colors after creating a plot window with X and then cause the window to be redrawn it does not redraw in the correct colors Wh
90. h dependence of x2ms x3ms VDS dependence of mus Ix3ms Length dependence of x3ms wx3ms Width dependence of x3ms ud VGS dependence of mobility lu0 Length dependence of u0 wu0 Width dependence of u0 x2u0 VBS dependence of u0 1x2u0 Length dependence of x2u0 wx2u0 Width dependence of x2u0 ul VDS depence of mobility velocity saturation lul Length dependence of ul wul Width dependence of ul x2ul VBS depence of ul Ix2ul Length depence of x2ul wx2ul Width depence of x2ul x3ul VDS depence of ul Ix3ul Length dependence of x3u1 wx3ul Width depence of x3ul nO Subthreshold slope InO Length dependence of n0 wn0 Width dependence of nO nb VBS dependence of subthreshold slope Inb Length dependence of nb wnb Width dependence of nb nd VDS dependence of subthreshold slope Ind Length dependence of nd wnd Width dependence of nd continued Spice3f User s Manual 109 APPENDIX B MODEL AND DEVICE PARAMETERS BSIM1 model input output parameters continued tox Gate oxide thickness in um temp Temperature in degree Celcius vdd Supply voltage to specify mus cgso Gate source overlap capacitance per unit channel width m cgdo Gate drain overlap capacitance per unit channel width m cgbo Gate bulk overlap capacitance per unit channel length m Xpart Flag for channel charge partitioning rsh Source drain diffusion sheet resistance in ohm per square js Source drain junction saturation current per unit area pb Source drain junction built in po
91. he diff command Overrides the name used for generating rspice runs default is rsh The machine to use for remote SPICE 3 runs instead of the default one see the description of the rspice command below The name of the remote program to use in the rspice command Stop between each graph plotted and wait for the user to type return be fore continuing A list of the directories to search when a source command is given The default is the current directory and the standard spice library usr localNib spice or whatever LIBPATH is defined to in the Spice3 source The program to use for the aspice command The default is cad bin spice The mfb name of the current terminal If this is degrees then all the trig functions will use degrees instead of radians User s Manual Spice3f unixcom verbose diff_vntol width x11lineararcs xbrushheight xbrushwidth xfont INTERACTIVE INTERPRETER VARIABLES 5 5 If a command isn t defined try to execute it as a UNIX command Set ting this option has the effect of giving a rehash command below This is useful for people who want to use nutmeg as a login shell Be verbose This is midway between echo and debug cpdebug The absolute voltage tolerance used by the diff command The width of the page for asciiplot and print col Some X11 implementations have poor arc drawing If you set this op tion Spice3 will plot using an approximation to the curve using straight li
92. hen this option has no ef fect hcopydev If this is set when the hardcopy command is run the resulting file is automatically printed on the printer named hcopydev with the com mand lpr Phcopydev g file hcopyfont This variable specifies the font name for hardcopy output plots The value is device dependent hcopyfontsize This is a scaling factor for the font used in hardcopy plots hcopydevtype height history Iprplots Iprps nfreqs nobreak noasciiplotvalue noclobber noglob nogrid nomoremode nonomatch nosort noprintscale Spice3f INTERACTIVE INTERPRETER CONTROL STRUCTURES This variable specifies the type of the printer output to use in the hard copy command If hcopydevtype is not set plot 5 format is assumed The standard distribution currently recognizes postscript as an alterna tive output format When used in conjunction with hcopydev hcopy devtype should specify a format supported by the printer The length of the page for asciiplot and print col The number of events to save in the history list This is a printf 3s style format string used to specify the command to use for sending plot 5 style plots to a printer or plotter The first parameter supplied is the printer name the second parameter supplied is a file name containing the plot Both parameters are strings It is trivial to cause Spice3 to abort by supplying a unreasonable format string This is a printf 3s style format stri
93. here are several tables for each type of device supported by Input parameters to instances and models are parameters that can occur on an instance or model definition line in the form keyword value where keyword is the parameter name as given in the tables Default input parameters such as the resistance of a resistor or the capacitance of a capacitor obviously do not need the keyword specified Output parameters are those additional parameters which are available for many types of instances for the output of operating point and debugging information These parameters are specified as 29 device keyword and are available for the most recent point computed or if specified in a save statement for an entire simulation as a normal output vector Thus to monitor the gate to source capaci tance of a MOSFET a command save ml1 cgs given before a transient simulation causes the specified capacitance value to be saved at each timepoint and a subsequent command such as plot m1 cgs produces the desired plot Note that the show command does not use this format Some variables are listed as both input and output and their output simply returns the previously input value or the default value after the simulation has been run Some parameter are input only because the output system can not handle variables of the given type yet or the need for them as output variables has not been apparen
94. hese two types of transfer functions cover all the cases and one can find the poles zeros of functions like input output impedance and voltage gain The input and output ports are specified as two pairs of nodes The pole zero analysis works with resistors capacitors inductors linear controlled sources indepen dent sources BJTs MOSFETs JFETs and diodes Transmission lines are not supported The method used in the analysis is a sub optimal numerical search For large circuits it may take a considerable time or fail to find all poles and zeros For some circuits the method becomes lost and finds an excessive number of poles or zeros 1 1 5 Small Signal Distortion Analysis The distortion analysis portion of SPICE computes steady state harmonic and intermodulation pro ducts for small input signal magnitudes If signals of a single frequency are specified as the input to the 2 User s Manual Spice3f INTRODUCTION TYPES OF ANALYSIS 1 1 5 circuit the complex values of the second and third harmonics are determined at every point in the circuit If there are signals of two frequencies input to the circuit the analysis finds out the complex values of the circuit variables at the sum and difference of the input frequencies and at the difference of the smaller fre quency from the second harmonic of the larger frequency Distortion analysis is supported for the following nonlinear devices diodes DIO BJT JFET MOS FETs
95. itudes and phases are specified by the arguments of the DIS TOFI keyword in the input file lines for the input sources see the description for independent sources The arguments of the DISTOF2 keyword are not relevant in this case The analysis produces information about the A C values of all node voltages and branch currents at the harmonic frequencies 2F1 and 3F1 vs the input frequency F1 as it is swept A value of 1 as a complex distortion output signifies cos 27 2F1 t at 2F1 and cos 27 3F1 t at 3F1 using the convention that 1 at the input fundamental fre quency is equivalent to cos 27FIt The distortion component desired 2F1 or 3F1 can be selected using commands in nutmeg and then printed or plotted Normally one is interested primarily in the magnitude of the harmonic components so the magnitude of the AC distortion value is looked at It should be noted that these are the A C values of the actual harmonic components and are not equal to HD2 and HD3 To obtain HD2 and HD3 one must divide by the corresponding A C values at F1 obtained from an AC line This division can be done using nutmeg commands If the optional FLOVERF parameter is specified it should be a real number between and not equal to 0 0 and 1 0 in this case DISTO does a spectral analysis It considers the circuit with sinusoidal inputs at two different frequencies F1 and F2 F1 is swept according to the DISTO control line options exactly as in the AC
96. levels 1 2 3 4 BSIM1 5 BSIM2 and 6 and MESFETS All linear devices are automatically sup ported by distortion analysis If there are switches present in the circuit the analysis continues to be accu rate provided the switches do not change state under the small excitations used for distortion calculations 1 1 6 Sensitivity Analysis Spice3 will calculate either the DC operating point sensitivity or the AC small signal sensitivity of an output variable with respect to all circuit variables including model parameters Spice calculates the difference in an output variable either a node voltage or a branch current by perturbing each parameter of each device independently Since the method is a numerical approximation the results may demonstrate second order affects in highly sensitive parameters or may fail to show very low but non zero sensitivity Further since each variable is perturb by a small fraction of its value zero valued parameters are not analyized this has the benefit of reducing what is usually a very large amount of data 1 1 7 Noise Analysis The noise analysis portion of SPICE does analysis device generated noise for the given circuit When provided with an input source and an output port the analysis calculates the noise contributions of each device and each noise generator within the device to the output port voltage It also calculates the input noise to the circuit equivalent to the output noise referred to th
97. lytic model accurate in the short channel region MOS4 3 4 and MOSS 5 are the BSIM Berkeley Short channel IGFET Model and BSIM2 MOS2 MOS3 and MOS4 include second order effects such as channel length modulation subthreshold conduction scattering limited velocity saturation small size effects and charge controlled capacitances 1 1 TYPES OF ANALYSIS 1 1 1 DC Analysis The dc analysis portion of SPICE determines the dc operating point of the circuit with inductors shorted and capacitors opened The dc analysis options are specified on the DC TF and OP control lines A dc analysis is automatically performed prior to a transient analysis to determine the transient ini tial conditions and prior to an ac small signal analysis to determine the linearized small signal models for nonlinear devices If requested the dc small signal value of a transfer function ratio of output variable to input source input resistance and output resistance is also computed as a part of the dc solution The dc analysis can also be used to generate dc transfer curves a specified independent voltage or current source is stepped over a user specified range and the dc output variables are stored for each sequential source value 1 1 1 INTRODUCTION TYPES OF ANALYSIS 1 1 2 AC Small Signal Analysis The ac small signal portion of SPICE computes the ac output variables as a function of frequency The program first computes the dc operating point
98. maximum reverse beta reverse current emission coefficient reverse Early voltage corner for reverse beta high current roll off B C leakage saturation current B C leakage emission coefficient zero bias base resistance current where base resistance falls halfway to its min value minimum base resistance at high currents emitter resistance collector resistance B E zero bias depletion capacitance B E built in potential B E junction exponential factor ideal forward transit time coefficient for bias dependence of TF voltage describing VBC dependence of TF high current parameter for effect on TF excess phase at freq 1 0 TF 2PD Hz B C zero bias depletion capacitance B C built in potential User s Manual units lt 7 DPD 0 Sec default 1 0e 16 100 1 0 infinite infinite 0 1 5 1 1 infinite infinite 0 2 0 infinite RB 0 75 0 33 infinite 0 75 example 1 0e 15 100 1 200 0 01 1 0e 13 2 0 1 1 200 0 01 1 0e 13 1 5 100 0 1 10 2pF 0 6 0 33 0 1ns 2pF 0 5 area Spice3f CIRCUIT ELEMENTS AND MODELS TRANSISTORS AND DIODES 3 4 4 name parameter units default example area 29 MJC B C junction exponential factor 0 33 0 5 30 XCJC fraction of B C depletion capacitance 1 connected to internal base node 31 TR ideal reverse transit time sec 0 10ns 32 CJS zero bias collector substrate capacitance F 0 2pF 33 VJS substrate junction built in potenti
99. mber FLOVERF1 should ideally be an irrational number and that since this is not possible in practice efforts should be made to keep the denominator in its fractional representation as large as possible certainly above 3 for accurate results i e if FLOVERF1 is represented as a fraction A B where A and B are integers with no common factors B should be as large as possible note that A lt B because F2LOVERF is constrained to be lt 1 To illustrate why consider the cases where F2OVERF1 is 49 100 and 1 2 In a spectral analysis the outputs produced are at F1 F2 F1 F2 and 2 F1 F2 In the latter case F1 F2 F2 so the result at the F1 F2 component is erroneous because there is the strong fundamental F2 component at the same frequency Also F1 F2 2 F1 F2 in the latter case and each result is erroneous individually This problem is not there in the case where FAOVERF1 49 100 because F1 F2 51 100 F1 lt gt 49 100 F1 F2 In this case there are two very closely spaced frequency components at F2 and F1 F2 One of the advantages of the Volterra series technique is that it computes distortions at mix frequencies expressed symbolically i e n Fl m F2 therefore one is able to obtain the strengths of distortion components accurately even if the separation between them is very small as opposed to transient analysis for example The disadvantage is of course that if two of the mix frequencies coincide the results are not merge
100. modeling real devices such as MOSFETS the on resistance should be adjusted to a realistic level depending on the size of the device being modeled If a wide range of ON to OFF resistance must be used in the switches ROFF RON gt l1e 12 then the tolerance on errors allowed during transient analysis should be decreased by using the OPTIONS control line and specifying TRTOL to be less than the default value of 7 0 When switches are placed around capacitors then the option CHGTOL should also be reduced Suggested values for these two options are 1 0 and 1e 16 respectively These changes inform SPICE3 to be more careful around the switch points so that no errors are made due to the rapid change in the circuit 18 User s Manual Spice3f CIRCUIT ELEMENTS AND MODELS VOLTAGE AND CURRENT SOURCES 3 2 3 2 VOLTAGE AND CURRENT SOURCES 3 2 1 Independent Sources General form VXXXXXXX N N lt lt DC gt DC TRAN VALUE gt lt AC lt ACMAG lt ACPHASE gt gt gt lt DISTOF1 lt FIMAG lt FIPHASE gt gt gt lt DISTOF2 lt F2MAG lt F2PHASE gt gt gt IYYYYYYY N N lt lt DC gt DC TRAN VALUE gt lt AC lt ACMAG lt ACPHASE gt gt gt lt DISTOF1 lt F1IMAG lt F1PHASE gt gt gt lt DISTOF2 lt F2MAG lt F2PHASE gt gt gt Examples vec 10 0 DC 6 VIN 13 2 0 001 AC 1 SIN O 1 1MEG ISRC 23 21 AC 0 333 45 0 SFFM 0 1 10K 5 1K VMEAS 12 9 VCARRIER 1 0 DISTOF1 0 1 90 0 VMODULATOR
101. name is the name of a list variable it is shifted to the left by number elements i e the number leftmost elements are removed The default varname is argv and the default number is 1 5 3 45 Show List device state General Form show devices parameters Old Form show v device name The show command prints out tables summarizing the operating condition of selected devices much like the spice2 operation point summary If device is missing a default set of devices are list ed if device is a single letter devices of that type are listed if device is a subcircuit name beginning man and ending in only devices in that subcircuit are shown end the name in a double man to get dev ices within sub subcircuits recursively The second and third forms may be combined letter subcircuit or letter subcircuit to select a specific type of device from a subcircuit A device s full name may be specified to list only that device Finally devices may be selected by model by using the form modelname or subcircuit modelname or letter subcircuit modelname If no parameters are specified the values for a standard set of parameters are listed If the list of parameters contains a the default set of parameters is listed along with any other specified parameters For both devices and parameters the word all has the obvious meaning Note there must be man spaces separating the
102. nce of source rd Drain conductance drainconductance Conductance of drain gm Transconductance gds Drain Source conductance gmb Bulk Source transconductance gmbs gbd Bulk Drain conductance gbs Bulk Source conductance cbd Bulk Drain capacitance cbs Bulk Source capacitance cgs Gate Source capacitance ced Gate Drain capacitance cgb Gate Bulk capacitance cqgs Capacitance due to gate source charge storage cqgd Capacitance due to gate drain charge storage cqgb Capacitance due to gate bulk charge storage cqbd Capacitance due to bulk drain charge storage cqbs Capacitance due to bulk source charge storage cbd0 Zero Bias B D junction capacitance cbdsw0 cbs0 Zero Bias B S junction capacitance cbssw0 qgs Gate Source charge storage qgd Gate Drain charge storage qgb Gate Bulk charge storage qbd Bulk Drain charge storage qbs Bulk Source charge storage p Instaneous power Mos1 model parameters input only nmos N type MOSfet model pmos P type MOSfet model Mos1 model parameters input output vto Threshold voltage vt0 null kp Transconductance parameter gamma Bulk threshold parameter phi Surface potential lambda Channel length modulation rd Drain ohmic resistance continued 124 User s Manual Spice3f APPENDIX B MODEL AND DEVICE PARAMETERS Mos 1 model input output parameters continued rs Source ohmic resistance cbd B D junction capacitance cbs B S junction capacitance is Bulk junc
103. nd for the calculation of the actual resistance value from strictly geometric informa tion and the specifications of the process If VALUE is specified it overrides the geometric information and defines the resistance If MNAME is specified then the resistance may be calculated from the process information in the model MNAME and the given LENGTH and WIDTH If VALUE is not specified then MNAME and LENGTH must be specified If WIDTH is not specified then it is taken from the default Spice3f User s Manual 13 3 1 2 CIRCUIT ELEMENTS AND MODELS ELEMENTARY DEVICES width given in the model The optional TEMP value is the temperature at which this device is to operate and overrides the temperature specification on the OPTION control line 3 1 3 Semiconductor Resistor Model R The resistor model consists of process related device data that allow the resistance to be calculated from geometric information and to be corrected for temperature The parameters available are name parameter units default example TCl first order temperature coeff Q C 0 0 TC2 second order temperature coeff QC 0 0 RSH sheet resistance Q 50 DEFW default width meters le 6 2e 6 NARROW narrowing due to side etching meters 0 0 le 7 TNOM parameter measurement temperature C 27 50 The sheet resistance is used with the narrowing parameter and L and W from the resistor device to determine the nominal resistance by the formula R RSH L N
104. nes The height of the brush to use if X is being run The width of the brush to use if X is being run The name of the X font to use when plotting data and entering labels The plot may not look good if this is a variable width font There are several set variables that Spice3 uses but Nutmeg does not They are editor modelcard noaskquit nobjthack noparse nosubckt renumber subend subinvoke substart Spice3f The editor to use for the edit command The name of the model card normally model Do not check to make sure that there are no circuits suspended and no plots unsaved Normally Spice3 warns the user when he tries to quit if this is the case Assume that BJTs have 4 nodes Don t attempt to parse input files when they are read in useful for de bugging Of course they cannot be run if they are not parsed Don t expand subcircuits Renumber input lines when an input file has include s The card to end subcircuits normally ends The prefix to invoke subcircuits normally x The card to begin subcircuits normally subckt User s Manual 91 5 6 INTERACTIVE INTERPRETER MISCELLANEOUS 5 6 MISCELLANEOUS If there are subcircuits in the input file Spice3 expands instances of them A subcircuit is delimited by the cards subckt and ends or whatever the value of the variables substart and subend is respectively An instance of a subcircuit is created by specifying a device with type
105. ng used to specify the command to use for sending PostScript plots to a printer or plotter The first param eter supplied is the printer name the second parameter supplied is a file name containing the plot Both parameters are strings It is trivial to cause Spice3 to abort by supplying a unreasonable format string The number of frequencies to compute in the fourier command De faults to 10 Don t have asciiplot and print col break between pages Don t print the first vector plotted to the left when doing an asciiplot Don t overwrite existing files when doing IO redirection Don t expand the global characters P and This is the de fault Don t plot a grid when graphing curves but do label the axes If nomoremode is not set whenever a large amount of data is being printed to the screen e g the print or asciiplot commands the output is stopped every screenful and continues when a carriage return is typed If nomoremode is set then data scrolls off the screen without check If noglob is unset and a global expression cannot be matched use the global characters literally instead of complaining Don t have display sort the variable names Don t print the scale in the leftmost column when a print col command is given User s Manual 5 4 9 89 5 5 numdgt plottype polydegree polysteps program prompt rawfile diff_reltol remote_shell rhost rprogram
106. nt line defines the contents of a tabular listing of one to eight output variables PRTYPE is the type of the analysis DC AC TRAN NOISE or DISTO for which the specified outputs are desired The form for voltage or current output variables is the same as given in the previous section for the print command Spice2 restricts the output variable to the following forms though this restriction is not enforced by Spice3 V N1 lt N2 gt specifies the voltage difference between nodes N1 and N2 If N2 and the preceding comma is omitted ground 0 is assumed See the print command in the previous section for more details For compatibility with spice2 the following five additional values can be accessed for the ac analysis by replacing the V in V N1 N2 with VR real part VI imaginary part VM magnitude VP phase VDB 20 logl0 magnitude ANALYSES AND OUTPUT CONTROL BATCH OUTPUT 4 4 I VXXXXXXX specifies the current flowing in the independent voltage source named VXXXXXXX Positive current flows from the positive node through the source to the negative node For the ac analysis the corresponding replacements for the letter I may be made in the same way as described for voltage outputs Output variables for the noise and distortion analyses have a different general form from that of the other analyses There is no limit on the number of PRINT lines for each type of analysis 4 4 3 PLOT Lines General form
107. o you can put it into a file with asciiplot args gt file The set options width height and nobreak determine the width and height of the plot and whether there are page breaks respectively Note that you will have problems if you try to asciiplot something with an X scale that isn t monotonic i e something like sin TIME because asciiplot uses a simple minded linear interpolation 5 3 5 Aspice Asynchronous spice run General Form aspice input file output file Start a SPICE 3 run and when it is finished load the resulting data The raw data is kept in a tem porary file If output file is specified then the diagnostic output is directed into that file otherwise it is thrown away 5 3 6 Bug Mail a bug report General Form bug Send a bug report Please include a short summary of the problem the version number and name of the operating system that you are running the version of Spice that you are running and the relevant spice input file If you have defined BUGADDR the mail is delivered to there 5 3 7 Cd Change directory General Form cd directory Change the current working directory to directory or to the user s home directory if none is given 66 User s Manual Spice3f INTERACTIVE INTERPRETER COMMANDS 5 3 8 5 3 8 Destroy Delete a data set General Form destroy plotnames all Release the memory holding the data for the specified runs 5 3 9 Dc Perform a DC
108. ode gnode Number of gate node snode Number of source node dprimenode Number of internal drain node sprimenode Number of internal source node vgs Gate Source voltage ved Gate Drain voltage cg Gate capacitance cd Drain capacitance ced Gate Drain capacitance gm Transconductance gds Drain Source conductance ggs Gate Source conductance ggd Gate Drain conductance cqgs Capacitance due to gate source charge storage cqgd Capacitance due to gate drain charge storage qgs Gate Source charge storage qgd Gate Drain charge storage Source current continued Spice3f User s Manual 121 APPENDIX B MODEL AND DEVICE PARAMETERS MES instance output only parameters continued p Power dissipated by the mesfet MES model parameters input only nmf N type MESfet model pmf P type MESfet model MES model parameters input output vtO Pinch off voltage vto null alpha Saturation voltage parameter beta Transconductance parameter lambda Channel length modulation parm b Doping tail extending parameter rd Drain ohmic resistance TS Source ohmic resistance cgs G S junction capacitance cgd G D junction capacitance pb Gate junction potential is Junction saturation current fc Forward bias junction fit parm kf Flicker noise coefficient af Flicker noise exponent MES model parameters output only type N type or P type MESfet model gd Drain conduc
109. of mu40 wmu40 Width dependence of mu40 mu4b VBS dependence of mu4 Imu4b Length dependence of mu4b wmu4b Width dependence of mu4b mu4g VGS dependence of mu4 Imu4g Length dependence of mu4g wmu4g Width dependence of mu4g ua0 Linear VGS dependence of mobility lua0 Length dependence of ua0 wua0 Width dependence of ua0 uab VBS dependence of ua luab Length dependence of uab wuab Width dependence of uab ub0 Quadratic VGS dependence of mobility lub0O Length dependence of ub0 wub0 Width dependence of ub0 ubb VBS dependence of ub lubb Length dependence of ubb wubb Width dependence of ubb uld VDS depence of mobility lu10 Length dependence of u10 wul0 Width dependence of u10 ulb VBS depence of ul lulb Length depence of ulb wulb Width depence of ulb uld VDS depence of ul luld Length depence of uld wuld Width depence of uld nO Subthreshold slope at VDS 0 VBS 0 InO Length dependence of nO continued 112 User s Manual Spice3f APPENDIX B MODEL AND DEVICE PARAMETERS BSIM2 model input output parameters continued wn0 Width dependence of nO nb VBS dependence of n Inb Length dependence of nb wnb Width dependence of nb nd VDS dependence of n Ind Length dependence of nd wnd Width dependence of nd vof0 Threshold voltage offset AT VDS 0 VBS 0 Ivof0 Length dependence of vof0 wvoft0 Width dependence of vof0 vofb VBS dependence of vof lvofb Length dependence of vofb wvofb Width dependence of
110. of the circuit and determines linearized small signal models for all of the nonlinear devices in the circuit The resultant linear circuit is then analyzed over a user specified range of frequencies The desired output of an ac small signal analysis is usually a transfer function voltage gain transimpedance etc If the circuit has only one ac input it is convenient to set that input to unity and zero phase so that output variables have the same value as the transfer function of the output variable with respect to the input 1 1 3 Transient Analysis The transient analysis portion of SPICE computes the transient output variables as a function of time over a user specified time interval The initial conditions are automatically determined by a dc analysis All sources which are not time dependent for example power supplies are set to their dc value The tran sient time interval is specified on a TRAN control line 1 1 4 Pole Zero Analysis The pole zero analysis portion of SPICE computes the poles and or zeros in the small signal ac transfer function The program first computes the dc operating point and then determines the linearized small signal models for all the nonlinear devices in the circuit This circuit is then used to find the poles and zeros of the transfer function Two types of transfer functions are allowed one of the form output voltage input voltage and the other of the form output voltage input current T
111. onstraint on these node voltages is removed This is the preferred method since it allows SPICE to compute a con sistent dc solution Spice3f User s Manual 49 4 2 2 ANALYSES AND OUTPUT CONTROL INITIAL CONDITIONS 4 3 ANALYSES 4 3 1 AC Small Signal AC Analysis General form AC DEC ND FSTART FSTOP AC OCT NO FSTART FSTOP AC LIN NP FSTART FSTOP Examples AC DEC 10 1 10K AC DEC 10 1K 100MEG AC LIN 100 1 100HZ DEC stands for decade variation and ND is the number of points per decade OCT stands for octave variation and NO is the number of points per octave LIN stands for linear variation and NP is the number of points FSTART is the starting frequency and FSTOP is the final frequency If this line is included in the input file SPICE performs an AC analysis of the circuit over the specified frequency range Note that in order for this analysis to be meaningful at least one independent source must have been speci fied with an ac value 4 3 2 DC DC Transfer Function General form DC SRCNAM VSTART VSTOP VINCR SRC2 START2 STOP2 INCR2 Examples DC VIN 0 25 5 0 0 25 DC VDS 0 10 5 VES 05 1 DC VCE 0 10 25 IB 0 10U 1U The DC line defines the dc transfer curve source and sweep limits again with capacitors open and inductors shorted SRCNAM is the name of an independent voltage or current source VSTART VSTOP and VINCR are the starting final and incrementing values res
112. or the job to complete and passes output from the re mote job to the user s standard output When the job is finished the data is loaded in as with aspice If the variable rhost is set nutmeg connects to this host instead of the default remote Spice3 server machine This command uses the rsh command and thereby requires authentication via a rhosts file or other equivalent method Note that rsh refers to the remote shell program which may be remsh on your system to override the default name of rsh set the variable remote_shell If the variable rprogram is set then rspice uses this as the pathname to the program to run on the remote system Note rspice will not acknowledge elements that have been changed via the alter or alter mod commands 74 User s Manual Spice3f INTERACTIVE INTERPRETER COMMANDS 5 3 35 5 3 35 Run Run analysis from the input file General Form run rawfile Run the simulation as specified in the input file If there were any of the control lines ac op able interactively In Spice 3e and earlier versions the input file would be re read and any affects of the set or alter commands would be reversed This is no longer the affect Spice3f User s Manual 75 5 3 36 INTERACTIVE INTERPRETER COMMANDS 5 3 36 Rusage Resource usage General Form rusage resource Print resource usage statistics If any resources are given just print the usage of that resource Most re
113. ositive node of source neg_node Negative node of source Positive node of contr source Negative node of contr source i v P Output current Voltage across output Power B 25 VCVS Voltage controlled voltage source VCVS instance parameters input only Initial condition of controlling source VCVS instance parameters input output gain Voltage gain Spice3f User s Manual 137 APPENDIX B MODEL AND DEVICE PARAMETERS VCVS instance parameters output only pos_node neg_node cont_p_node cont_n_node Positive node of source Negative node of source Positive node of contr source Negative node of contr source i v P Output current Output voltage Power B 26 Vsource Independent voltage source Vsource instance parameters input only pulse Pulse description sine Sinusoidal source description sin Sinusoidal source description exp Exponential source description pwl Piecewise linear description sffm Single freq FM descripton ac AC magnitude phase vector distof1 f1 input for distortion distof2 f2 input for distortion Vsource instance parameters input output de D C source value acmag A C Magnitude acphase A C Phase Vsource instance parameters output only pos_node Positive node of source neg_node Negative node of source function Function of the source order
114. ot as in the output for an AC analysis Finally the keyword polar to generate a polar plot To produce a smith plot use the keyword smith Note that the data is transformed so for smith plots you will see the data transformed by the function x 1 x 1 To produce a polar plot with a smith grid but without performing the smith transform use the keyword smithgrid 5 3 28 Print Print values General Form print col line expr Prints the vector described by the expression expr If the col argument is present print the vec tors named side by side If line is given the vectors are printed horizontally col is the default unless all the vectors named have a length of one in which case line is the default The options width length and nobreak are effective for this command see asciiplot If the expression is all all of the vectors available are printed Thus print col all gt file prints everything in the file in SPICE2 format The scale vector time frequency is always in the first column unless the variable noprintscale is true 72 User s Manual Spice3f INTERACTIVE INTERPRETER COMMANDS 5 3 29 5 3 29 Quit Leave Spice3 or Nutmeg General Form quit Quit nutmeg or spice 5 3 30 Rehash Reset internal hash tables General Form rehash Recalculate the internal hash tables used when looking up UNIX commands and make all UNIX commands in the user s PATH available for command completion This is usele
115. ough the inductor to N Note that the initial conditions if any apply only if the UIC option is specified on the TRAN analysis line 16 User s Manual Spice3f CIRCUIT ELEMENTS AND MODELS ELEMENTARY DEVICES 3 1 8 3 1 8 Coupled Mutual Inductors General form KXXXXXXX LYYYYYYY LZZZZZZZ VALUE Examples K43 LAA LBB 0 999 KXFRMR L1 12 0 87 LYYYYYYY and LZZZZZZZ are the names of the two coupled inductors and VALUE is the coefficient of coupling K which must be greater than 0 and less than or equal to 1 Using the dot convention place a dot on the first node of each inductor 3 1 9 Switches General form SXXXXXXX N N NC NC MODEL lt ON gt lt OFF gt WYYYYYYY N N VNAM MODEL lt ON gt lt OFF gt Examples sl 1 2 3 4 switchi ON s2 5 6 3 0 sm2 off Switchl 1 2 10 0 smodell wl 1 2 vclock switchmodl W2 3 0 vramp sml ON wreset 5 6 vclck lossyswitch OFF Nodes 1 and 2 are the nodes between which the switch terminals are connected The model name is mandatory while the initial conditions are optional For the voltage controlled switch nodes 3 and 4 are the positive and negative controlling nodes respectively For the current controlled switch the controlling current is that through the specified voltage source The direction of positive control ling current flow is from the positive node through the source to the negative node Spice3f User s Manual 17 3 1 10 CIRCUIT ELEM
116. p cap rsh Sheet resistance cj Bottom junction cap per area mj Bottom grading coefficient cjsw Side junction cap per area mjsw Side grading coefficient js Bulk jct sat current density tox Oxide thickness ld Lateral diffusion u0 Surface mobility uo null fc Forward bias ject fit parm nsub Substrate doping tpg Gate type nss Surface state density vmax Maximum carrier drift velocity xj Junction depth nfs Fast surface state density xd Depletion layer width alpha Alpha eta Vds dependence of threshold voltage delta Width effect on threshold input_delta null theta Vgs dependence on mobility kappa Kappa tnom Parameter measurement temperature kf Flicker noise coefficient af Flicker noise exponent Spice3f User s Manual 131 APPENDIX B MODEL AND DEVICE PARAMETERS Mos3 model parameters output only type N channel or P channel MOS B 20 Mos6 Level 6 MOSfet model with Meyer capacitance model Mos6 instance parameters input only off Device initially off ic Vector of D S G S B S voltages Mos6 instance parameters input output l Length w Width ad Drain area as Source area pd Drain perimeter ps Source perimeter nrd Drain squares nrs Source squares icvds Initial D S voltage icvgs Initial G S voltage icvbs Initial B S voltage temp Instance temperature Mos6 instance parameters output only id Drain cu
117. pectively The first example causes the value of the voltage source VIN to be swept from 0 25 Volts to 5 0 Volts in increments of 0 25 Volts A second source SRC2 may optionally be specified with associated sweep parameters In this case the first source is swept over its range for each value of the second source This option can be useful for obtaining semiconductor device output characteristics See the second example circuit description in Appendix A 50 User s Manual Spice3f ANALYSES AND OUTPUT CONTROL ANALYSES 4 3 2 4 3 3 DISTO Distortion Analysis General form DISTO DEC ND FSTART FSTOP lt F2OVERF1 gt DISTO OCT NO FSTART FSTOP lt F2OVERF1 gt DISTO LIN NP FSTART FSTOP lt F2OVERF1 gt Examples DISTO DEC 10 1kHz 100Mhz DISTO DEC 10 1kHz 100Mhz 0 9 The Disto line does a small signal distortion analysis of the circuit A multi dimensional Volterra series analysis is done using multi dimensional Taylor series to represent the nonlinearities at the operating point Terms of up to third order are used in the series expansions If the optional parameter F2LOVERF1 is not specified DISTO does a harmonic analysis i e it ana lyses distortion in the circuit using only a single input frequency F1 which is swept as specified by argu ments of the DISTO command exactly as in the AC command Inputs at this frequency may be present at more than one input source and their magn
118. pice3f ANALYSES AND OUTPUT CONTROL SIMULATOR VARIABLES OPTIONS 4 1 option METHOD name PIVREL x PIVTOL x RELTOL x TEMP x TNOM x TRTOL x TRYTOCOMPACT VNTOL x effect sets the numerical integration method used by SPICE Possible names are Gear or trapezoidal or just trap The default is trapezoidal resets the relative ratio between the largest column entry and an acceptable pivot value The default value is 1 0e 3 In the numerical pivoting algorithm the allowed minimum pivot value is determined by EPSREL AMAX1 PIVREL MAXVAL PIVTOL where MAXVAL is the maximum element in the column where a pivot is sought partial pivoting resets the absolute minimum value for a matrix entry to be accepted as a pivot The default value is 1 0e 13 resets the relative error tolerance of the program The default value is 0 001 0 1 Resets the operating temperature of the circuit The default value is 27 deg C 300 deg K TEMP can be overridden by a temperature specification on any temperature dependent instance resets the nominal temperature at which device parameters are measured The default value is 27 deg C 300 deg K TNOM can be overridden by a specification on any temperature dependent device model resets the transient error tolerance The default value is 7 0 This parameter is an estimate of the factor by which SPICE overestimates the actual truncation error Applicable only to the LT
119. pice3f User s Manual 59 5 INTERACTIVE INTERPRETER i or I Run in interactive mode This is useful if the standard input is not a terminal but interactive mode is desired Command completion is not available unless the standard input is a terminal however This option is valid for Spice3 only r rawfile or P rawfile Use rawfile as the default file into which the results of the simulation are saved This option is valid for Spice3 only Further arguments to spice are taken to be Spice3 input files which are read and saved if running in batch mode then they are run immediately Spice3 accepts most Spice2 input file and output ascii plots fourier analyses and node printouts as specified in plot four and print cards If an out parameter is given on a width card the effect is the same as set width Since Spice3 ascii plots do not use multiple ranges however if vectors together on a plot card have different ranges they are not provide as much information as they would in Spice2 The output of Spice3 is also much less verbose than Spice2 in that the only data printed is that requested by the above cards For nutmeg further arguments are taken to be data files in binary or ascii format see sconvert 1 which are loaded into nutmeg If the file is in binary format it may be only partially completed useful for examining Spice2 output before the simulation is finished One file may contain any number of data sets
120. pletion capacitance formula width effect on threshold voltage MOS2 and MOS3 mobility modulation MOS3 only static feedback MOS3 only saturation field factor MOS3 only parameter measurement temperature User s Manual units meter meter cm Vs V cm 1 V C default 1 0 0 0 0 0 600 1 0e4 0 0 0 0 0 0 1 0 0 0 1 0 0 5 0 0 0 0 0 0 0 2 27 example Ip 0 8 700 1 0e4 0 1 0 3 5 0e4 5 0 1 0e 26 1 2 1 0 0 1 1 0 0 5 50 Spice3f CIRCUIT ELEMENTS AND MODELS TRANSISTORS AND DIODES 3 4 8 The level 4 and level 5 BSIM1 and BSIM2 parameters are all values obtained from process charac terization and can be generated automatically J Pierret 4 describes a means of generating a process file and the program Proc2Mod provided with SPICE3 converts this file into a sequence of BSIM1 MODEL lines suitable for inclusion in a SPICE input file Parameters marked below with an in the 1 w column also have corresponding parameters with a length and width dependency For example VFB is the basic parameter with units of Volts and LVFB and WVFB also exist and have units of Volt umeter The formula PL Pw P Po Leffective Weffective is used to evaluate the parameter for the actual device specified with Leffective Linput DL and Wertective Winput DW Note that unlike the other models in SPICE the BSIM model is designed for use with a process char acteriz
121. put to SPICE For details of the BSIM temperature adjust ment see 6 and 7 Temperature appears explicitly in the exponential terms of the BJT and diode model equations In addition saturation currents have a built in temperature dependence The temperature dependence of the saturation current in the BJT models is determined by T XTI T exp where k is Boltzmann s constant q is the electronic charge Eg is the energy gap which is a model Is T1 Is To k T T9 E q T To parameter and XTI is the saturation current temperature exponent also a model parameter and usual ly equal to 3 The temperature dependence of forward and reverse beta is according to the formula XTB T To where T and T are in degrees Kelvin and XTB is a user supplied model parameter Temperature ef PTD B To fects on beta are carried out by appropriate adjustment to the values of Br Ise Br and Isc spice model parameters BF ISE BR and ISC respectively Temperature dependence of the saturation current in the junction diode model is determined by xT T N To exp where N is the emission coefficient which is a model parameter and the other symbols have the same Is T1 Is To N k T To E q T To meaning as above Note that for Schottky barrier diodes the value of the saturation current tempera ture exponent XTI is usually 2 4 User s Manual Spice3f INTRODUCTION ANALYSI
122. ral form EXXXXXXX N N NC NC VALUE Examples El 2 3 14 1 2 0 N is the positive node and N is the negative node NC and NC are the positive and nega tive controlling nodes respectively VALUE is the voltage gain 3 2 2 3 Linear Current Controlled Current Sources General form FXXXXXXX N N VNAM VALUE Examples F1 13 5 VSENS 5 N and N are the positive and negative nodes respectively Current flow is from the positive node through the source to the negative node VNAM is the name of a voltage source through which the controlling current flows The direction of positive controlling current flow is from the positive node through the source to the negative node of VNAM VALUE is the current gain 24 User s Manual Spice3f CIRCUIT ELEMENTS AND MODELS VOLTAGE AND CURRENT SOURCES 3 2 2 4 3 2 2 4 Linear Current Controlled Voltage Sources General form HXXXXXXX N N VNAM VALUE Examples HX 5 17 VZ 0 5K N and N are the positive and negative nodes respectively VNAM is the name of a voltage source through which the controlling current flows The direction of positive controlling current flow is from the positive node through the source to the negative node of VNAM VALUE is the transresistance in ohms 3 2 3 Non linear Dependent Sources General form BXXXXXXX N N lt I EXPR gt lt V EXPR gt Examples B1 0 1 I cos v 1 sin v 2 B1 0 1 V In cos log v 1 2 2 v
123. reakpoint information General Form status Display all of the traces and breakpoints currently in effect 80 User s Manual Spice3f INTERACTIVE INTERPRETER COMMANDS 5 3 49 5 3 49 Step Run a fixed number of timepoints General Form step number Iterate number times or once and then stop 5 3 50 Stop Set a breakpoint General Form stop after n when value cond value Set a breakpoint The argument after n means stop after n iteration number n and the argu ment when value cond value means stop when the first value is in the given relation with the second value the possible relations being eq or equal to ne or lt gt __ not equal to gt or gt greater than It or lt less than ge or gt greater than or equal to le or lt __ less than or equal to IO redirection is disabled for the stop command since the relational operations conflict with it it doesn t produce any output anyway The values above may be node names in the running circuit or real values If more than one condition is given e g stop after 4 when v 1 gt 4 when v 2 lt 2 the conjunction of the conditions is implied 5 3 51 Tf Run a Transfer Function analysis General Form tf output_node input_source The tf command performs a transfer function analysis returning the transfer function output input output resistance and input resistance between the given output node and the given in put source The
124. rname where the value of the vari able is to appear The special variables and lt refer to the process ID of the program and a line of input which is read from the terminal when the variable is evaluated respectively If a variable has a name of the form amp word then word is considered a vector see above and its value is taken to be the value of the variable If foo is a valid variable and is of type list then the expression foo low high represents a range of elements Either the upper index or the lower may be left out and the reverse of a list may be obtained with foo len 0 Also the notation foo evaluates to 1 if the variable foo is defined 0 other wise and foo evaluates to the number of elements in foo if it is a list 1 if it is a number or string and 0 if it is a boolean variable History substitutions similar to C shell history substitutions are also available see the C shell manual page for all of the details The characters and have the same effects as they do in the C Shell i e home directory and alternative expansion It is possible to use the wildcard characters and also but only if you unset noglob first This makes them rather useless for typing algebraic expressions so you should set noglob again after you are done with wildcard expansion Note that the pattern abce matchs all characters except a b and c IO redirection is available the symbols gt gt gt
125. rrent cd Drain current is Source current ig Gate current ib Bulk current ibs B S junction capacitance ibd B D junction capacitance vgs Gate Source voltage vds Drain Source voltage vbs Bulk Source voltage vbd Bulk Drain voltage dnode Number of the drain node gnode Number of the gate node snode Number of the source node bnode Number of the node dnodeprime Number of int drain node snodeprime Number of int source node continued 132 User s Manual Spice3f APPENDIX B MODEL AND DEVICE PARAMETERS Mos6 instance output only parameters continued TS Source resistance sourceconductance Source conductance rd Drain resistance drainconductance Drain conductance von Turn on voltage vdsat Saturation drain voltage sourcevcrit Critical source voltage drainverit Critical drain voltage gmbs Bulk Source transconductance gm Transconductance gds Drain Source conductance gbd Bulk Drain conductance gbs Bulk Source conductance cgs Gate Source capacitance cgd Gate Drain capacitance cgb Gate Bulk capacitance cbd Bulk Drain capacitance cbs Bulk Source capacitance cbd0 Zero Bias B D junction capacitance cbdsw0O cbs0 Zero Bias B S junction capacitance cbssw0 cqgs Capacitance due to gate source charge storage cqgd Capacitance due to gate drain charge storage cqgb Capacitance due to gate bulk charge storage cqbd Capacitance due to bulk drain charge storage cqbs Capacitance due to bulk source charge storage
126. rs 2 through 15 are used in order for vectors plotted The value of the color variables should be names of colors which may be found in the file usr lib rgb txt combplot Plot vectors by drawing a vertical line from each point to the X axis as opposed to joining the points Note that this option is subsumed in the plottype option below cpdebug Print cshpar debugging information must be complied with the DCPDEBUG flag Unsupported in the current release debug If set then a lot of debugging information is printed must be compiled with the DFTEDEBUG flag Unsupported in the current release device The name dev tty of the graphics device If this variable isn t set then the user s terminal is used To do plotting on another monitor you probably have to set both the device and term variables If device is set to the name of a file nutmeg dumps the graphics control codes into this file this is useful for saving plots echo Print out each command before it is executed filetype This can be either ascii or binary and determines what format are The default is ascii fourgridsize How many points to use for interpolating into when doing fourier analysis gridsize If this variable is set to an integer this number is used as the number of equally spaced points to use for the Y axis when plotting Otherwise the current scale is used which may not have equally spaced points If the current scale isn t strictly monotonic t
127. rs Number of squares in source off Device is initially off vds Initial D S voltage vgs Initial G S voltage vbs Initial B S voltage BSIM1 model parameters input only nmos Flag to indicate NMOS pmos Flag to indicate PMOS BSIM1 model parameters input output vfb Flat band voltage lvfb Length dependence of vfb wvfb Width dependence of vfb phi Strong inversion surface potential Iphi Length dependence of phi wphi Width dependence of phi k1 Bulk effect coefficient 1 Ik1 Length dependence of k1 wkl Width dependence of k1 k2 Bulk effect coefficient 2 1k2 Length dependence of k2 wk2 Width dependence of k2 eta VDS dependence of threshold voltage leta Length dependence of eta weta Width dependence of eta x2e VBS dependence of eta 1x2e Length dependence of x2e continued 108 User s Manual Spice3f APPENDIX B MODEL AND DEVICE PARAMETERS BSIM1 model input output parameters continued wx2e Width dependence of x2e x3e VDS dependence of eta Ix3e Length dependence of x3e wx3e Width dependence of x3e dl Channel length reduction in um dw Channel width reduction in um muz Zero field mobility at VDS 0 VGS VTH x2mz VBS dependence of muz Ix2mz Length dependence of x2mz wx2mz Width dependence of x2mz mus Mobility at VDS VDD VGS VTH channel length modulation Imus Length dependence of mus wmus Width dependence of mus x2ms VBS dependence of mus lx2ms Length dependence of x2ms wx2ms Widt
128. s output only pos_node1 Positive node of end 1 of t line neg_nodel Negative node of end 1 of t line pos_node2 Positive node of end 2 of t line neg_node2 Negative node of end 2 of t line LTRA model parameters input output ltra LTRA model T Resistance per metre l Inductance per metre g null c Capacitance per metre len length of line nocontrol No timestep control steplimit always limit timestep to 0 8 delay of line continued 120 User s Manual Spice3f APPENDIX B MODEL AND DEVICE PARAMETERS LTRA model input output parameters continued nosteplimit don t always limit timestep to 0 8 delay of line lininterp use linear interpolation quadinterp use quadratic interpolation mixedinterp use linear interpolation if quadratic results look unacceptable truncnr use N R iterations for step calculation in LTRAtrunc truncdontcut don t limit timestep to keep impulse response calculation errors low compactrel special reltol for straight line checking compactabs special abstol for straight line checking LTRA model parameters output only rel Rel rate of change of deriv for bkpt abs Abs rate of change of deriv for bkpt B 16 MES GaAs MESFET model MES instance parameters input output is area Area factor icvds Initial D S voltage icvgs Initial G S voltage MES instance parameters output only off Device initially off dnode Number of drain n
129. s performed over the interval lt TSTOP period TSTOP gt where TSTOP is the final time specified for the transient analysis and period is one period of the fundamental frequency The dc component and the first nine harmonics are determined For maximum accuracy TMAX see the TRAN line should be set to period 100 0 or less for very high Q circuits 58 User s Manual Spice3f 5 INTERACTIVE INTERPRETER Spice3 consists of a simulator and a front end for data analysis and plotting The front end may be run as a separate stand alone program under the name Nutmeg Nutmeg will read in the raw data output file created by spice r or with the write command in an interactive Spice3 session Nutmeg or interactive Spice3 can plot data from a simulation on a graphics ter minal or a workstation display Most of the commands available in the interactive Spice3 front end are available in nutmeg where this is not the case Spice only commands have been marked with an asterisk Note that the raw output file is different from the data that Spice2 writes to the standard output which may also be produced by spice3 with the b command line option Spice and Nutmeg use the X Window System for plotting if they find the environment variable DISPLAY Otherwise a graphics terminal independent interface MFB is used If you are using X ona workstation the DISPLAY variable should already be set if you want to display graphics on a system dif
130. se the SAVE line see below may be used to record the value of internal device variables see Appendix B If a rawfile is not specified then output plots in line printer form and tables can be printed according to the PRINT PLOT and FOUR control lines described next PLOT PRINT and FOUR lines are meant for compatibility with Spice2 4 1 SIMULATOR VARIABLES OPTIONS Various parameters of the simulations available in Spice3 can be altered to control the accuracy speed or default values for some devices These parameters may be changed via the set command described later in the section on the interactive front end or via the OPTIONS line General form OPTIONS OPT1 OPT2 or OPT OPTVAL Examples OPTIONS RELTOL 005 TRTOL 8 Spice3f User s Manual 45 4 1 ANALYSES AND OUTPUT CONTROL SIMULATOR VARIABLES OPTIONS The options line allows the user to reset program control and user options for specific simulation pur poses Additional options for Nutmeg may be specified as well and take effect when Nutmeg reads the input file Options specified to Nutmeg via the set command are also passed on to SPICE3 as if specified on a OPTIONS line See the following section on the interactive command interpreter for the parameters which may be set with a OPTIONS line and the format of the set command Any combination of the fol lowing options may be included in any order x below repre
131. sents some positive number option effect ABSTOL x resets the absolute current error tolerance of the program The default value is 1 picoamp BADMOS3 Use the older version of the MOS3 model with the kappa discontinuity CHGTOL x resets the charge tolerance of the program The default value is 1 0e 14 DEFAD x resets the value for MOS drain diffusion area the default is 0 0 DEFAS x resets the value for MOS source diffusion area the default is 0 0 DEFL x resets the value for MOS channel length the default is 100 0 micrometer DEFW x resets the value for MOS channel width the default is 100 0 micrometer GMIN x resets the value of GMIN the minimum conductance allowed by the program The default value is 1 0e 12 ITL1 x resets the dc iteration limit The default is 100 ITL2 x resets the dc transfer curve iteration limit The default is 50 ITL3 x resets the lower transient analysis iteration limit the default value is 4 Note not implemented in Spice3 ITL4 x resets the transient analysis timepoint iteration limit the default is 10 ITL5 x resets the transient analysis total iteration limit the default is 5000 Set ITL5 0 to omit this test Note not implemented in Spice3 KEEPOPINFO Retain the operating point information when either an AC Distortion or Pole Zero analysis is run This is particularly useful if the circuit is large and you do not want to run a redundant OP analysis User s Manual S
132. setcire circuit name The current circuit is the one that is used for the simulation commands below When a circuit is loaded with the source command see below it becomes the current circuit 5 3 41 Setplot Switch the current set of vectors General Form setplot plotname Set the current plot to the plot with the given name or if no name is given prompt the user with a menu Note that the plots are named as they are loaded with names like tran1 or op2 These names are shown by the setplot and display commands and are used by diff below If the New plot item is selected the current plot becomes one with no vectors defined Note that here the word plot refers to a group of vectors that are the result of one SPICE run When more than one file is loaded in or more than one plot is present in one file nutmeg keeps them separate and only shows you the vectors in the current plot 5 3 42 Settype Set the type of a vector General Form settype type vector Change the type of the named vectors to type Type names can be found in the manual page for sconvert 5 3 43 Shell Call the command interpreter General Form shell command Call the operating system s command interpreter execute the specified command or call for in teractive use 78 User s Manual Spice3f INTERACTIVE INTERPRETER COMMANDS 5 3 44 5 3 44 Shift Alter a list variable General Form shift varname number If var
133. sform General Form fourier fundamental_frequency value Does a fourier analysis of each of the given values using the first 10 multiples of the fundamen tal frequency or the first nfregs if that variable is set see below The output is like that of the four Spice3 line The values may be any valid expression The values are interpolated onto a fixed space grid with the number of points given by the fourgridsize variable or 200 if it is not set The in terpolation is of degree polydegree if that variable is set or 1 If polydegree is 0 then no interpola tion is done This is likely to give erroneous results if the time scale is not monotonic though 5 3 17 Hardcopy Save a plot to a file for printing General Form hardcopy file plotargs Just like plot except creates a file called file containing the plot The file is an image in plot 5 format and can be printed by either the plot 1 program or Ipr with the g flag 5 3 18 Help Print summaries of Spice3 commands General Form help all command Prints help If the argument all is given a short description of everything you could possibly type is printed If commands are given descriptions of those commands are printed Otherwise help for only a few major commands is printed Spice3f User s Manual 69 5 3 18 INTERACTIVE INTERPRETER COMMANDS 5 3 19 History Review previous commands General Form history number Print out the history
134. sources require that a circuit be loaded Currently valid resources are elapsed The amount of time elapsed since the last rusage elaped call faults Number of page faults and context switches BSD only space Data space used time CPU time used so far temp Operating temperature thom Temperature at which device parameters were measured equations Circuit Equations time Total Analysis Time totiter Total iterations accept Accepted timepoints rejected Rejected timepoints loadtime Time spent loading the circuit matrix and RHS reordertime Matrix reordering time lutime L U decomposition time solvetime Matrix solve time trantime Transient analysis time tranpoints Transient timepoints traniter Transient iterations trancuriters Transient iterations for the last time point tranlutime Transient L U decomposition time transolvetime Transient matrix solve time everything All of the above listed incorrectly as Transient iterations per point 76 User s Manual Spice3f INTERACTIVE INTERPRETER COMMANDS 5 3 37 5 3 37 Save Save a set of outputs General Form save all output save all output Save a set of outputs discarding the rest If a node has been mentioned in a save command it appears in the working plot after a run has completed or in the rawfile if spice is run in batch mode If a node is traced or plotted see below it is also saved For backward compatibility if there are no save
135. ss unless you have set unixcom first see above 5 3 31 Reset Reset an analysis General Form reset Throw out any intermediate data in the circuit e g after a breakpoint or after one or more ana lyses have been done already and re parse the input file The circuit can then be re run from it s ini tial state overriding the affect of any set or alter commands In Spice 3e and earlier versions this was done automatically by the run command Spice3f User s Manual 73 5 3 32 INTERACTIVE INTERPRETER COMMANDS 5 3 32 Reshape Alter the dimensionality or dimensions of a vector General Form reshape vector vector or reshape vector vector dimension dimension or reshape vector vector dimension dimension This command changes the dimensions of a vector or a set of vectors The final dimension may be left off and it will be filled in automatically If no dimensions are specified then the dimensions of the first vector are copied to the other vectors An error message of the form dimensions of x were inconsistent can be ignored 5 3 33 Resume Continue a simulation after a stop General Form resume Resume a simulation after a stop or interruption control C 5 3 34 Rspice Remote spice submission General Form rspice input file Runs a SPICE 3 remotely taking the input file as a SPICE 3 input file or the current circuit if no argument is given Nutmeg or Spice3 waits f
136. t Many such input variables are available as output variables in a different format such as the initial condition vectors that can be retrieved as individual initial condition values Finally internally derived values are output only and are provided for debugging and operating point output pur poses Please note that these tables do not provide the detailed information available about the parameters provided in the section on each device and model but are provided as a quick reference guide Spice3f User s Manual 103 APPENDIX B MODEL AND DEVICE PARAMETERS B 1 URC Uniform R C line URC instance parameters input output l Length of transmission line n Number of lumps URC instance parameters output only pos_node Positive node of URC neg_node Negative node of URC gnd Ground node of URC URC model parameters input only urc Uniform R C line model URC model parameters input output k Propagation constant fmax Maximum frequency of interest rperl Resistance per unit length cperl Capacitance per unit length isperl Saturation current per length rsperl Diode resistance per length B 2 ASRC Arbitrary Source ASRC instance parameters input only i Current source v Voltage source ASRC instance parameters output only i Current through source v Voltage across source pos_node Positive Node neg_node Neg
137. t parm tpg Gate type nsub Substrate doping nss Surface state density tnom Parameter measurement temperature 134 User s Manual Spice3f APPENDIX B MODEL AND DEVICE PARAMETERS Mos6 model parameters output only type N channel or P channel MOS B 21 Resistor Simple linear resistor Resistor instance parameters input output resistance Resistance temp Instance operating temperature l Length w Width Resistor instance parameters output only i Current p Power Resistor model parameters input only T Device is a resistor model Resistor model parameters input output rsh Sheet resistance narrow Narrowing of resistor tcl First order temp coefficient tc2 Second order temp coefficient defw Default device width tnom Parameter measurement temperature B 22 Switch Ideal voltage controlled switch Switch instance parameters input only on off Switch initially closed Switch initially open Spice3f User s Manual 135 APPENDIX B MODEL AND DEVICE PARAMETERS Switch instance parameters input output pos_node neg_node Positive node of switch Negative node of switch Switch instance parameters output only cont_p_node cont_n_node i Positive contr node of switch Positive contr node of switch Switch current p Switch power Switch
138. tance gs Source conductance depl_cap Depletion capacitance vcrit Critical voltage 122 User s Manual Spice3f APPENDIX B MODEL AND DEVICE PARAMETERS B 17 Mos1 Level 1 MOSfet model with Meyer capacitance model Mos1 instance parameters input only off Device initially off ic Vector of D S G S B S voltages Mos1 instance parameters input output l Length w Width ad Drain area as Source area pd Drain perimeter ps Source perimeter nrd Drain squares nrs Source squares icvds Initial D S voltage icvgs Initial G S voltage icvbs Initial B S voltage temp Instance temperature Mos1 instance parameters output only id Drain current is Source current ig Gate current ib Bulk current ibd B D junction current ibs B S junction current vgs Gate Source voltage vds Drain Source voltage vbs Bulk Source voltage vbd Bulk Drain voltage dnode Number of the drain node gnode Number of the gate node snode Number of the source node bnode Number of the node dnodeprime Number of int drain node snodeprime Number of int source node von vdsat Saturation drain voltage sourcevcrit Critical source voltage drainvcrit Critical drain voltage TS Source resistance continued Spice3f User s Manual 123 APPENDIX B MODEL AND DEVICE PARAMETERS Mos 1 instance output only parameters continued sourceconductance Conducta
139. tential mj Source drain bottom junction capacitance grading coefficient pbsw Source drain side junction capacitance built in potential mjsw Source drain side junction capacitance grading coefficient cj Source drain bottom junction capacitance per unit area cjsw Source drain side junction capacitance per unit area wdf Default width of source drain diffusion in um dell Length reduction of source drain diffusion B 5 BSIM2 Berkeley Short Channel IGFET Model BSIM2 instance parameters input only Vector of DS GS BS initial voltages BSIM2 instance parameters input output l Length w Width ad Drain area as Source area pd Drain perimeter ps Source perimeter nrd Number of squares in drain nrs Number of squares in source off Device is initially off vds Initial D S voltage vgs Initial G S voltage vbs Initial B S voltage 110 User s Manual Spice3f APPENDIX B MODEL AND DEVICE PARAMETERS BSIM2 model parameters input only nmos Flag to indicate NMOS pmos Flag to indicate PMOS BSIM2 model parameters input output vib Flat band voltage lvfb Length dependence of vfb wvtfb Width dependence of vfb phi Strong inversion surface potential Iphi Length dependence of phi wphi Width dependence of phi kl Bulk effect coefficient 1 Ik1 Length dependence of k1 wkl Width dependence of k1 k2 Bulk effect coefficient 2 1k2 Length dependenc
140. tion sat current pb Bulk junction potential cgso Gate source overlap cap cgdo Gate drain overlap cap cgbo Gate bulk overlap cap rsh Sheet resistance cj Bottom junction cap per area mj Bottom grading coefficient cjsw Side junction cap per area mjsw Side grading coefficient js Bulk jct sat current density tox Oxide thickness ld Lateral diffusion u0 Surface mobility uo null fc Forward bias jct fit parm nsub Substrate doping tpg Gate type nss Surface state density tnom Parameter measurement temperature kf Flicker noise coefficient af Flicker noise exponent Mos1 model parameters output only type N channel or P channel MOS Spice3f User s Manual 125 APPENDIX B MODEL AND DEVICE PARAMETERS B 18 Mos2 Level 2 MOSfet model with Meyer capacitance model Mos2 instance parameters input only off Device initially off ic Vector of D S G S B S voltages Mos2 instance parameters input output l Length w Width ad Drain area as Source area pd Drain perimeter ps Source perimeter nrd Drain squares nrs Source squares icvds Initial D S voltage icvgs Initial G S voltage icvbs Initial B S voltage temp Instance operating temperature Mos2 instance parameters output only id Drain current cd ibd B D junction current ibs B S junction current is Source current ig Gate current ib Bulk current vgs Gate Source voltage vds Drain Source voltag
141. tude of vector ph vector The phase of vector j vector i sqrt 1 times vector real vector The real component of vector imag vector The imaginary part of vector db vector 20 log10 mag vector log vector The logarithm base 10 of vector In vector The natural logarithm base e of vector exp vector e to the vector power abs vector The absolute value of vector sqrt vector The square root of vector sin vector The sine of vector cos vector The cosine of vector tan vector The tangent of vector atan vector The inverse tangent of vector norm vector The vector normalized to i e the largest magnitude of any component is 1 rnd vector A vector with each component a random integer between 0 and the absolute value of the vectors s corresponding com ponent mean vector The result is a scalar a length 1 vector that is the mean of the elements of vector User s Manual 61 5 1 INTERACTIVE INTERPRETER EXPRESSIONS FUNCTIONS AND CONSTANTS vector number The result is a vector of length number with elements 0 1 number 1 If number is a vector then just the first element is taken and if it isn t an integer then the floor of the magni tude is used length vector The length of vector interpolate plot vector The result of interpolating the named vector onto the scale of the current plot This function uses the variable polydegree to determine the degree of interpolation deriv vector
142. unction In interactive mode the command syntax is the same except that the first field is PZ instead of PZ To print the results one should use the command print all Spice3f User s Manual 53 4 3 6 ANALYSES AND OUTPUT CONTROL ANALYSES 4 3 7 SENS DC or Small Signal AC Sensitivity Analysis General form SENS OUTVAR SENS OUTVAR AC DEC ND FSTART FSTOP SENS OUTVAR AC OCT NO FSTART FSTOP SENS OUTVAR AC LIN NP FSTART FSTOP Examples SENS V 1 OUT SENS V OUT AC DEC 10 100 100k SENS I VTEST The sensitivity of OUTVAR to all non zero device parameters is calculated when the SENS analysis is specified OUTVAR is a circuit variable node voltage or voltage source branch current The first form calculates sensitivity of the DC operating point value of OUTVAR The second form calculates sensitivity of the AC values of OUTVAR The parameters listed for AC sensitivity are the same as in an AC analysis see AC above The output values are in dimensions of change in output per unit change of input as opposed to percent change in output or per percent change of input 4 3 8 TF Transfer Function Analysis General form OUTVAR INSRC Examples V 5 3 VIN TF I VLOAD VIN The TF line defines the small signal output and input for the dc small signal analysis OUTVAR is the small signal output variable and INSRC is the small signal input source
143. uration voltage parameter 1 V 2 2 ai 5 LAMBDA channel length modulation parameter 1 V 0 1 0e 4 6 RD drain ohmic resistance Q 0 100 aj 7 RS source ohmic resistance Q 0 100 x 8 CGS zero bias G S junction capacitance F 0 SpF 9 CGD zero bias G D junction capacitance F 0 lpF k 10 PB gate junction potential V 1 0 6 11 KF flicker noise coefficient 0 12 AF flicker noise exponent 1 13 FC coefficient for forward bias 0 5 depletion capacitance formula Spice3f User s Manual 43 3 4 10 CIRCUIT ELEMENTS AND MODELS TRANSISTORS AND DIODES 44 User s Manual Spice3f 4 ANALYSES AND OUTPUT CONTROL The following command lines are for specifying analyses or plots within the circuit description file Parallel commands exist in the interactive command interpreter detailed in the following section Speci fying analyses and plots or tables in the input file is useful for batch runs Batch mode is entered when either the b option is given or when the default input source is redirected from a file In batch mode the analyses specified by the control lines in the input file e g ac won gt tran etc are immediately executed 1 unless control lines exists see the section on the interactive command interpretor If the r rawfile option is given then all data generated is written to a Spice3 rawfile The rawfile may be read by either the interactive mode of Spice3 or by nutmeg see the previous section for details In this ca
144. vice models and subcircuit calls see below Note that any device models or subcircuit definitions included as part of a subcircuit definition are strictly local i e such models and definitions are not known outside the subcircuit definition Also any element nodes not included on the SUBCKT line are strictly local with the exception of 0 ground which is always glo bal 2 4 2 ENDS Line General form ENDS lt SUBNAM gt Examples ENDS OPAMP The Ends line must be the last one for any subcircuit definition The subcircuit name if in cluded indicates which subcircuit definition is being terminated if omitted all subcircuits being de fined are terminated The name is needed only when nested subcircuit definitions are being made 10 User s Manual Spice3f CIRCUIT DESCRIPTION SUBCIRCUITS 2 4 3 2 4 3 Subcircuit Calls General form XYYYYYYY N1 lt N2 N3 gt SUBNAM Examples X1 2 4 17 3 1 MULTI Subcircuits are used in SPICE by specifying pseudo elements beginning with the letter X fol lowed by the circuit nodes to be used in expanding the subcircuit Spice3f User s Manual 11 2 5 CIRCUIT DESCRIPTION COMBINING FILES INCLUDE LINES 2 5 COMBINING FILES INCLUDE LINES General form INCLUDE filename Examples INCLUDE users spice common wattmeter cir Frequently portions of circuit descriptions will be reused in several input files particularly with 1 common models and
145. vofb vofd VDS dependence of vof lvofd Length dependence of vofd wvofd Width dependence of vofd aid Pre factor of hot electron effect 1ai0 Length dependence of ai0 wail Width dependence of ai0 aib VBS dependence of ai laib Length dependence of aib waib Width dependence of aib bid Exponential factor of hot electron effect 1bi0 Length dependence of bi0 wbi0 Width dependence of bi0 bib VBS dependence of bi Ibib Length dependence of bib wbib Width dependence of bib vghigh Upper bound of the cubic spline function Ivghigh Length dependence of vghigh wvghigh Width dependence of vghigh vglow Lower bound of the cubic spline function lvglow Length dependence of vglow wvglow Width dependence of vglow tox Gate oxide thickness in um temp Temperature in degree Celcius vdd Maximum Vds veg Maximum Vgs vbb Maximum Vbs cgso Gate source overlap capacitance per unit channel width m cgdo Gate drain overlap capacitance per unit channel width m cgbo Gate bulk overlap capacitance per unit channel length m Xpart Flag for channel charge partitioning continued Spice3f User s Manual 113 APPENDIX B MODEL AND DEVICE PARAMETERS BSIM2 model input output parameters continued rsh Source drain diffusion sheet resistance in ohm per square js Source drain junction saturation current per unit area pb Source drain junction built in potential mj Source drain bottom junction capacitance grading coef
146. xamples T1 10 2 0 Z0 50 TD 10NS N1 and N2 are the nodes at port 1 N3 and N4 are the nodes at port 2 ZO is the characteristic impedance The length of the line may be expressed in either of two forms The transmission delay TD may be specified directly as TD 10ns for example Alternatively a frequency F may be given together with NL the normalized electrical length of the transmission line with respect to the wavelength in the line at the frequency F If a frequency is specified but NL is omitted 0 25 is assumed that is the frequency is assumed to be the quarter wave frequency Note that although both forms for expressing the line length are indicated as optional one of the two must be specified Note that this element models only one propagating mode If all four nodes are distinct in the actual circuit then two modes may be excited To simulate such a situation two transmission line elements are required see the example in Appendix A for further clarification The optional initial condition specification consists of the voltage and current at each of the transmission line ports Note that the initial conditions if any apply only if the UIC option is specified on the TRAN control line Note that a lossy transmission line see below with zero loss may be more accurate than than the lossless transmission line due to implementation details 3 3 2 Lossy Transmission Lines General form OXXXXXXX N1 N2 N3 N4

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