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1. PCB Bottom Layer Li DATE CODE RIRE LR NAMI cap XX Pty Ltd 2003 172. From equation 6 OA lt I lt 4 7A If these limits do not suit the application then resistors can be replaced on the Evaluation Board according to equations 4 5 and 6 7 0 Connecting the Evaluation Board The evaluation board is inserted into the Host and the CF Card under test is inserted into the Evaluation Board as shown in figure 2 The supercapacitor terminals are joined to the connector labeled CON CAPXX The terminals of CON CAPXX are labeled GND OUT and VCC OUT These are to be connected as close as possible to the ground and positive supply of the Pulsed Load respectively There are many power architectures where the supercapacitor may be placed For example the Pulsed Load may be a GPRS module or a DC DC converter For the least voltage droop and maximum benefit from the supercapacitor s low ESR it is important to minimise the resistance between the supercapacitor and its load Therefore the wires from CON CAPXX to the Pulsed Load should be as short and as thick as practical Warning As stated in section 2 0 if Vcc is chosen to be 5V then the voltage at the supercapacitor must be dropped to lt 4 5V by including a series diode The diode D10 was chosen such that the minimum load current quiescent current gives an acceptable voltage drop The minimum load can be increased by reducing the supercapacitor balancing resistors R5 amp R6 The CF specification states that the 5V fall is 10 and therefore in theory
3. PGOOD is included to indicate when the supercapacitor is charged to the appropriate level The vo tage on the supercapacitor is compared to a reference using a comparator with adjustable thresholds and hysteresis The thresholds need to be adjustable on an Evaluation Board because different applications will reguire different load voltages The hysteresis also needs to be adjustable because a step in load current will cause a step voltage on the supercapacitor because of the supercapacitor s Equivalent Series Resistance ESR cap XX Pty Ltd 2003 4 www cap xx com APPEB1004 User s Manual Rev 1 0 March 2003 Since this step voltage part of the ripple is a normal occurrence it would not be desirable for this to indicate that the supercapacitor is undercharged Power Good LED Online LED Off V Vru Figure 1 Power Good Hysteresis As in Figure 1 the high threshold Vrh is the voltage at which the supercapacitor s unloaded voltage becomes acceptable The hysteresis Vw is the voltage that when subtracted from the high threshold gives the low threshold Vo It indicates that the supercapacitor is undercharged Vo is set by the factory at 3 2V and Vy is set at 0 3V therefore Vo is 2 9V PGOOD has a header labeled on the Evaluation Board as H PGOOD It is an active high output signal that can be used to signal an external circuit that the supercapacitor is fully charged A green LED is also included to
4. Module DC DC converter V www cap xx com APPEB1004 User s Manual Rev 1 0 March 2003 Connections common to both Mode 1 and 2 are a Connect external wires thick and short from CON_CAPXX to the Pulsed loads on the CF Card Under Test b Place jumpers on pins 3 and 4 of J VCC13 IN and J VCC38 IN Remember to use the series diode remove J 5V if using the 5V rail c Place jumpers on J_RED amp YLW J GREEN J_PGOOD and J ENABLE d Remove jumpers on J_VS1 J VS2 Mode 1 is accomplished by the following a Connect jumpers on J_VCC13 and J VCC38 b Remove jumpers across pins 1 2 of both JVCC_13_OUT and JVCC_38_OUT Make sure that Vcc on the CF card under test is not connected to the Pulsed Load V Otherwise Vcc will be short circuited by the supercapacitor when it is discharged and the current limit circuit is not in this path Mode 2 is when the supercapacitor supplies both the Vcc for the PC Card Under Test Other Circuitry as well as the Pulsed loads In this mode all supplies are delayed according to equation 1 Any voltage ripple on the supercapacitor due to large currents will appear on the Vcc rail Mode 2 is accomplished by the following a Remove the jumpers on J_VCC13 and J VCC38 b Either ensure that Vcc on the CF card under test is connected to the Pulsed Load V and supply the load via thick wires
5. as per Figure 2 or place jumpers across pins 1 2 of both JVCC 13 OUT and IMC 38 OUT There are many other modes available The Evaluation board is designed for flexibility by allowing each section to be isolated or connected to external circuits NOTE Care must be taken in which ever mode is chosen so that the charge up time of the supercapacitor does not affect the operation of any reset or power rail monitoring circuitry etc As described in section 4 0 and 5 0 the J_ENABLE and H_PGOOD signals may need to be interfaced with the CF Card Under Test for proper control 7 2 Current Measurement Currents can be measured with a current probe or a voltage across a sense resistor A jumper can be replaced by an external wire loop which the current probe can clamp on If a current probe is not available then a sense resistor can be used in cap XX Pty Ltd 2003 10 www cap xx com APPEB1004 User s Manual Rev 1 0 March 2003 place of the jumpers The voltage dropped across the resistor divided by the value of the resistor equals the current 7 3 Card Detect The correct insertion of a CF Card is detected when both pins 25 and 26 are grounded These pins are typically grounded on the CF Card Under Test However the ground signal can also be replicated by jumpering CD1 and CD2 to ground on J Test1 and J_Test2 The removal and insertion of the card can be simulated by depressing and releasing either of t
6. desired current limit is 500mA then an R lt 6 62 would draw more than 500mA R can then be chosen to be the next standard value lt 6 60 ie 5 702 From equation 3 the power rating of the 5 7Q resistor would have to be gt 1 43W In this particular example and according to equation 2 R can also be a short circuit as this would not overload M1 b Place an ammeter in series with the power supply Turn on the power supply and adjust Current Limit R2 slowly clockwise until the desired current limit is reached Warning Do not increase the current limit above that used in equations 2 and 3 for any longer than a few seconds otherwise Ml or R may be destroyed c Remove R turn off the power supply 6 2 Adjusting Hysteresis Width with PGOOD Feedback R23 NOTE Vy is adjusted before V7 because the Vr adjustment is affected by Vy Therefore if adjustments are made in this section then section 6 3 should be checked a If the CF card is to be driven from the 5V rail then remove the jumper across J 5V otherwise if the PC Card is to be driven from the 3 3V rail then fit the jumper across J_5V b Connect a load power resistor RL of around 10Q 47Q from VCC_OUT to GND_OUT on CON_CAPXX This ensures that the supercapacitor voltage will change in reasonable time when the power supply voltage is changed Note the power rating of RH has to be a minimum value according to equation 3 c Turn th
7. indicate this condition It is labeled on the Evaluation Board as Power Good 6 0 Adjusting the Circuit Equipment needed Adjustable power supply multi meter and various power resistors Warning Be careful not to exceed the supercapacitor rated voltage 4 5V or the maximum continuous power rating for M1 2 5W a Ensure the following jumpers are fitted JLRED amp YLW J GREEN J_PGOOD J ENABLE J_VCC13_IN pins 3 and 4 J_VCC38_IN pins 3 and 4 and J_5V Remove jumpers on J_VCC13_OUT and J_VCC38_OUT Pin 1 is marked with V b Turn Current Limit R2 fully anti clockwise no current Set the power supply voltage to say 3 3VDC Ensure that the power supply can supply the desired current Connect its negative lead to J_GND1 or J_GND2 Connect the positive lead to pin 1 of J_VCC13_IN c Set the power supply output voltage to a value lt 4 5V 6 1 Adjusting the Current Limit with Current Limit Ro Warning the maximum average power rating for M1 is 2 5W see section 3 0 a Connect a load resistor to CON CAPXX R that draws just over the desired current limit from the CF host typically 500mA Note the power cap XX Pty Ltd 2003 5 www cap xx com APPEB1004 User s Manual Rev 1 0 March 2003 rating of the resistor is according to equation 3 and R has a minimum value according to equation 2 For example if the supply voltage is 3 3V and the
8. is 1 65W 5 and the 5V rail is 2 5W 10 The Evaluation Board has an adjustable current limit circuit The current limit can be adjusted from OA to 4 5A by using the potentiometer R2 It is labeled on the Evaluation Board as Current Limit Turning the potentiometer clockwise will increase the current limit The MOSFET M1 and Sense Resistor R1 can withstand up to 4 5A whilst the supercapacitor is being charged They cannot however withstand the 4 5A into a short circuit indefinitely There is no short circuit protection The MOSFET M1 has a maximum continuous power dissipation of 2 5W Therefore any continuous load resistance R has a minimum value as given by equation 2 SECHER L Ry Noch gt 2 5 2 R also has a minimum power rating according to equation 3 Pe IR input current 1 3 v2 Pr gt 2 input current lt 1 Ri 4 0 Enable The current limit circuit has an enable feature Enab e is an active low signal and the two pin jumper is labeled on the Evaluation Board as J ENABLE It is an input signal to the Evaluation Board and it can be jumpered to ground to be permanently enabled or it can be externally driven by an open collector or drain When J ENABLE is externally driven it allows the supercapacitor to be charged only when the User s Card is ready Pin 2 of J ENABLE is the control input and Pin 1 is permanently connected to ground 5 0 Power Good The Power Good circuit
9. the desired Vrh Turn PGOOD Reference R15 slowly anti clockwise until the Power Good LED turns ON c Check that the Power Good LED turns ON and OFF at the desired levels This can be done by varying the power supply voltage in both directions so that Vg is less than Vr and then greater than Vo d Remove R 6 4 Replacing the Potentiometers with Fixed Resistors The potentiometers on the Evaluation Board are included to provide flexibility in evaluating many different applications In a final design for production the resistance of the potentiometers would have been decided and therefore they can be replaced with fixed resistors This section includes the equations that can be used to theoretically determine the value of these resistors The value of these resistors can also be found practically by measuring the resistance of the potentiometers out of circuit once the circuit has been successfully adjusted as above R22 R23 2 4 Vw R15 R16 2 19N 5 53 Vw Vig Roe 6 56 I cap XX Pty Ltd 2003 7 WWW Cap XX com APPEB1004 User s Manual Rev 1 0 March 2003 6 5 Limits of Adjustment From the schematic in the Appendix it can be seen that R22 47kQ R23 500kQ potentiometer R15 50kQ potentiometer R16 3k9Q R2 2kQ potentiometer From equation 4 0 1V lt Vy lt 1 2V From equation 5 2 3V lt Viy lt 4 7V Vw 0 1V 2 4V lt Vry lt 4 9V Vw 0 3V 2 8V lt Vry lt 5 7V Vw 1 2V
10. the rail may be as high as 5 5V In this rare case a voltage drop of 1V is required If D10 does not give enough voltage drop for the minimum current case then two diodes in series may be needed Alternatively a diode with different characteristics can be substituted Note The number 1 pin of a header or jumper has a small triangle pointing to it cap XX Pty Ltd 2003 8 www cap xx com APPEB1004 User s Manual Rev 1 0 March 2003 Pulsed loads Hnor GND J VCC13 OUT z Pi 1 E88UE s SAL 88 88 88 RI2 RIT R18 on T CE DE 8 R Supercopocitor Evaluation Board Part No APPEB1004 www cap XX Com Figure 2 Typical connection of Evaluation Board 7 1 Vec Modes Figure 2 shows the typical way for connecting the Evaluation Board Vcc on the CF Card Under Test is generally supplied by one of two modes Mode 1 being the most common is when Vcc is supplied directly from the host via J CF HEADER pins 13 and 38 These Vcc rails supply all the circuitry on the CF Card Under Test Other Circuitry except for the Pulsed loads V which is supplied by the supercapacitor with the external wires In this mode Vcc is available to the Other Circuitry as soon as the CF Card Under Test is powered up whereas the supercapacitor supply to the Pulsed loads is delayed by the charge up time of the supercapacitor according to equation 1 cap XX Pty Ltd 2003 9 eg GPRS
11. PPEB1003 User s Manual Rev 1 0 February 2003 PCB Top Overlay N 8 18 sa J CF HEADER pa 4H LT 7 3 J Testl 25 A 50 25 J CF SOCKET s CD2 b Jee Dos 3 DOI DOO STSCHG s vs2 AOO A0 SPKR 8 A02 A03 INPACK 1 J vec38 0 A04 A05 RESET Anel VCC13 CSEL J_vec13 A07 A08 Apel 0E AOWR 5 J vs A10 CE1 9 DO7 Do6 2 D05 DO4 o 1 Ke GND 2 E z d 26 1 30 LE Jg Power Good GREEN COusv R TT no C5 vots UL 133 Volts IC J g I J_RED amp YLW Cou ee J PGOOD se H PGOOD I J ENABLE CO H_CAPXX CON_CAPXX 2 N 2 2 Q x x 3 a 6 H 3 Q s en 07 S 3228 VE E eS JE Mi Mane wo be 9 a PGOOD Feedback PGOOD Reference Jaa LI ORH LARIO U d i Supercopocitor Evaluation Board T7 Part No APPEB1004 WWW COP XX COM Current Limit E a cap XX Pty Ltd 2003 13 www cap xx com APPEB1003 User s Manual Rev 1 0 February 2003 PCB Top Layer cap XX Pty Ltd 2003 14 Wwww cap xx com APPEB1003 User s Manual Rev 1 0 February 2003 PCB 2 Layer 0000000000000 200000000000 cap XX Pty Ltd 2003 15 WWW Cap xx com APPEB1003 User s Manual Rev 1 0 February 2003 PCB 3 Layer AN NA o Ga OO 10 OO Ga OO 00 010 OC OO 070 O ro La cap XX Pty Ltd 2003 16 WWW Cap xx com APPEB1003 User s Manual Rev 1 0 February 2003
12. an be dropped to lt 4 5V by removing a jumper which introduces a series diode in the voltage supply lines on the Evaluation Board see section 7 0 A yellow LED is included to indicate when Vcc is 3 3V or greater It is labeled on the Evaluation Board as 3 3 Volts If Vcc is disconnected or if the Evaluation Board is removed from the host and there is still charge on the supercapacitor then current will flow through the body diode of M1 and through the yellow LED also through the red LED if the supercapacitor is greater than 4 2V The intensity of the yellow LED then gives an indication of the voltage remaining on the supercapacitor If however the series diode has been included to reduce the 5V rail to 4 5V then the LEDs will not be ON when Vcc is disconnected 2 1 Charge Time A fully discharged supercapacitor will be charged to Vcc after a certain time t This time will depend on the current limit IL Vcc and the capacitance C The equation is _ Vcc IL t c 1 cap XX Pty Ltd 2003 3 www cap xx com APPEB1004 User s Manual Rev 1 0 March 2003 3 0 Current Limit Circuits that employ large capacitors generally need a current limiting circuit to alleviate the current in rush problem The CF specification states that the peak current is 500mA from either the 3 3V or 5V rail The tolerance on the 3 3V rail is 5 and the tolerance on the 5V rail is 10 Therefore the peak power from the 3 3V rail
13. e PGOOD Reference R to around mid position about 11 turns from either limit d Decide the high threshold voltage Vrh the low threshold voltage Vo and the hysteresis voltage width Vw Vw Vr Vol Vo has to be greater than the minimum voltage required by the Pulsed Load Vw has to be greater than the expected voltage droop due to the ESR and capacitor discharge etc e The LED labeled 3 3 Volts should now be ON and the LED labeled Power Good should also be ON If Power Good is not ON then turn PGOOD Reference Ris anticlockwise slowly until the Power Good LED is ON cap XX Pty Ltd 2003 6 www cap xx com APPEB1004 User s Manual Rev 1 0 March 2003 f Connect a voltmeter across the supercapacitor which is also across R and CON CAPXX Vz Slowly reduce the power supply voltage and note Vp When the Power Good LED turns OFF Slowly increase the power supply voltage and note V when the Power Good LED turns ON The difference between the two readings is the hysteresis voltage width Vw g Adjust PGOOD Feedback R23 anti clockwise increases Vw and repeat e amp f until the desired hysteresis width is achieved 6 3 Adjusting the High Threshold with PGOOD Reference Ris a Turn PGOOD Reference R15 fully clockwise and then reduce the power supply voltage until the Power Good LED is OFF b Adjust the power supply voltage so V equals
14. he two micro switches SW_CD1 or SW CD2 7 4 Voltage Select The CF Card Under Test chooses the Vcc voltage rail using pin 33 VS1 If VS1 is grounded then a Vcc of 3 3V is requested if it is left floating then 5V is requested This signal can be replicated with J_VS1 Placing a jumper on J_VS1 forces the Signal to ground and therefore requests 3 3V J_VS2 is undefined and should be left floating 8 0 Disconnecting Circuits for Reduced Load The minimum voltage on some loads may be critical Any current that the Evaluation Board uses contributes to the droop on the input voltage If the droop becomes excessive then some of the functions on the Evaluation Board can be disconnected to save current and therefore increase the input voltage The red and yellow LEDS can be disconnected by removing the jumper J_RED amp YLW The green LED can be disconnected by removing the jumper J_GREEN The entire PGOOD circuit can be disconnected by removing the jumper J PGOOD cap XX Pty Ltd 2003 11 www cap xx com APPEB1003 User s Manual Rev 1 0 February 2003 Appendix Schematic The board can be configured such that it is a pure extender card with no extra loading or circuitry ie all pins straight through cap XX Pty Ltd 2003 12 www cap xx com A
15. pendix 12 Schematic 12 PCB Top Overlay 13 PCB Top Layer 14 PCB 2 Layer 15 PCB 3 Layer 16 PCB Bottom Layer 17 cap XX Pty Ltd 2003 2 WWW Cap Xx com APPEB1004 User s Manual Rev 1 0 March 2003 1 0 Introduction This Users Manual is for the cap XX Compact Flash CF Extender and Supercapacitor Evaluation Board Part No APPEB1004 This board was designed for the evaluation of a supercapacitor in a CF Card The application of supercapacitors is limited only by the user s imagination Typical examples are CF PC Card PDA Smartphone GPRS and other handheld eguipment The Evaluation Board is a CF Extender with a supercapacitor a current limit circuit and other features An excellent source for information on Supercapacitors and free downloads are available on the cap XX website at www cap xx com In the following description of operation it may be helpful to refer to the Evaluation Board Schematic in the Appendix 2 0 Input Voltage The supercapacitors for the Evaluation Board are rated at 4 5V and therefore it is not recommended that the input voltage Vcc be greater than 4 5V If Vcc is 5V then the Equivalent Series Resistance ESR rise rate of the supercapacitor is increased and the lifetime will be reduced A red LED is included to indicate that Vcc is too high and it starts to glow when Vcc is approximately 4 2V The red LED is labeled on the Evaluation Board as 5 Volts If Vcc is 5V then the voltage c
16. www cap xx com APPEB1004 User s Manual Rev 1 0 March 2003 cap XX Compact Flash Extender and Supercapacitor Evaluation Board Part No APPEB1004 User s Manual Revision 1 0 March 2003 Evaluation Board Features CF Extender Supercapacitor two form factors Adjustable current limit circuit with Supercapacitor charge enable 3 3V and 5V input LEDs Supercapacitor voltage comparator with adjustable threshold adjustable hysteresis and Power Good LED Card Detect switches to simulate card removal and insertion Sub circuits can be disconnected to reduce the load Test points jumpers and I O connectors Typical Supercapacitor Applications Compact Flash PC card PDA Smartphone GPRS Handheld Equipment Load Leveling cap XX Pty Ltd 2003 www cap xx com APPEB1004 User s Manual Rev 1 0 March 2003 Contents 1 0 Introduction 3 2 0 Input Voltage 3 2 1 Charge Time 3 3 0 Current Limit 4 4 0 Enable 4 50 Power Good 4 6 0 Adjusting the Circuit 5 6 1 Adjusting the Current Limit with Current Limit Ro 6 6 2 Adjusting Hysterisis Width with PGOOD Feedback R23 6 6 3 Adjusting the High Threshold with PGOOD Reference Ri5 7 6 4 Replacing the Potentiometers with Fixed Resistors 7 8 6 5 Limits of Adjustment 7 0 Connecting the Evaluation Board 8 7 1 Vec Modes 9 7 2 Current Measurement 10 7 3 Card Detect 11 7 4 Voltage Select 11 8 0 Disconnecting Circuits for Reduced Load 11 Ap
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