Oscilloscope - Tektronix TDS3000 Series Guide
Contents
1. 11 Tektronix TDS3000 Series Oscilloscope Guide v1 1 Portland State University Probe Compensation Some probes have a built in compensation network that can be adjusted to better match a probe s unique operating characteristics to the oscilloscope s inputs Use the following procedure to compensate a probe 1 Connect the probe to the desired input channel on the oscilloscope 2 On the front panel of the oscilloscope attach the probe s tip to the Probe Comp terminal and the probe s ground lead to the chassis ground terminal On the TDS3000 series the terminals are located by the Channel 2 input connector PROBE COMP generates a 5 volt square wave at 1 kHz 3 Push the AUTOSET button to acquire the test signal 4 Use the probe s adjustment tool to make the square wave have a flat top p t beens vae EEA bane rege aeara Lapsed ideneael Es wrd er Yori f a aw f l i n rieien a ach TUG WISONS CRT IT TsomVv Ch TV M230ps Chi 7 Tsomv TY 250H CHT J TEOMV Over compensated Under compensated Properly compensated Figure 4 Effects of probe compensation on a square wave 12 Tektronix TDS3000 Series Oscilloscope Guide v1 1 Portland State University 5 Simplified Measurement Procedure 1 Before making any connections verify that the test circuit will not produce voltage or current levels that could damage the oscilloscope 2 Turn on the oscilloscope The instrument is more accurate if2. OSCILLOSCOPE GUIDE Tektronix TDS3000 Series Department of Electrical amp Computer Engineering Tektronix TDS3000 Series Oscilloscope Guide v1 1 Portland State University Contents 1 INTRODUCTION EES AE EE AE EE Ge GE Ge EE OG GE EEE 2 2 OSCILLOSCOPE OVERVIEW ee ee ee ee ee ee ee 2 3 INSTRUMENT FRONT PANEL ee ee ee ee ee ee ee ee ee 3 E Pow r Switch Se EE ee de Ge GE A Ge GE Ge GE EE ee Go ee ee ee ee Ede 3 gt Floppy Disk DIVERS eN ia EG N GN Re Ge Di ee SN 3 gt Hard Copy BUUEOR ass oes ei ERG ene Se Ie Dek Re AE De RA ge sided Ge GE IE Ee Re A GN Ge es ee 3 Re General Purpose KOEN dae ee ve ed ee Re er n ee oe ee eg 3 P CD Je EO ER N Ea EE EENE OE AE EAN N 4 gt Bottom screen and Side screen Menu ButtONS ee ee ee ee ee se ee ee 4 PB VERTICAL Section COntrols cece eeeeeecccccsececccccscccccsescecccsusceceatsecccassececsueseeceatseeceuaeseeceans 5 gt HORIZONTAL Section Controls es ee ee se ee ee ee se ee ee ee ee ee ee ee ee ee ee ee ee ee 6 P TRIGGER Section Controls ee ee ee ee ee ee ee ee ee ee ee ee ee RENE EARE 7 PD ACQUIRE Section Controls ee ee ee se ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee 8 MENU Controls EE ect cate EE EDE Ge SG Ee Ge De GE ee ee Ge Ge Ge ee GE GE ee De Ee ee 8 PP NOE Connectors es ie Ee Re GR ee GR Ge ee SR de ED a Ee eg 9 4 PASSIVE PROBES ee ee ee ee ee ee ee ee ee ee ee 10 5 SIMPLIFIED MEASUREMENT PROCEDURE
3. 1 Portland State University gt Input Connectors External probes are attached to the female BNC input connectors on the front panel of the oscilloscope Each input connector is surrounded by the TekProbe interface ring If a probe supports the interface the oscilloscope autodetects the probe attenuation factor e g 1X or 10X the coupling and the input resistance If the probe does not use the interface then these settings must be set manually Tektronix TDS3000 Series Oscilloscope Guide v1 1 Portland State University 4 Passive Probes A typical passive probe consists of a cable with a male BNC connector on one end and a retractable hook tip or a pointed tip with ground clip on the other The BNC side attaches to one of the oscilloscope s inputs while the probe tip is attached to a measurement point in the test circuit The probe tip is where the voltage signal enters the probe and is then carried through the cable to the center pin of the BNC connector The ground clip provides the ground reference from the test circuit to the outer shield of the BNC connector Retractable Hook Tip Adapter Clip on Ground Lead This end attaches to the oscilloscope input LS Adjustment Tool Figure 2 General purpose voltage probe with accessories Copyright Tektronix Inc or Oscilloscope Circuit Probe Cable input Being s FRESE SESH SGeReees 006 EBEREBEREEHEE REDE OoOo O EE ia N EEN Measured R proe
4. 9 MO GND EEEE ee ve EE NE Ve ee E ETE WE Capes ao De hee EE EDE EE EE EE GEE EE EEN GEN DEE ER A 10X probe uses a 9 MQ series All cables have some TDS2000 series scopes resistor to increase the total amount of shunt have a fixed input input resistance seen by the capacitance resistance of 1 MQ measured device to 10 MQ Figure 3 Simplified circuit model of a 10X probe connected to an oscilloscope s input channel For a 1X probe Rprobe and Cprobe are omitted and replaced by a direct wire path 10 Tektronix TDS3000 Series Oscilloscope Guide v1 1 Portland State University These are some important characteristics of a probe e Bandwidth This is the highest frequency signal that the probe can accurately pass through to the oscilloscope for measurement A common metric is the frequency at which the measured signal amplitude has decreased by 3 dB from the original value e Attenuation The attenuation factor determines how much the probe reduces the amplitude of the input signal before it enters the oscilloscope Typical probes are either 1X no attenuation at all or 10X amplitude is divided by 10 Some probes support manual switching between 1X and 10X modes Attenuation also affects the total input resistance that is seen by the circuit being tested Note The attenuation factor setting in the vertical section of the oscilloscope should be changed to match the attenuation factor of the probe The display
5. currently chosen to be controlled When a channel button is pressed the associated channel becomes active and appears on the screen VERTICAL POSITION knob This knob moves the position of the currently selected waveform either up or down on the LCD screen It does not change the vertical scale VERTICAL SCALE knob This knob adjusts the vertical scale size of the currently selected waveform The vertical voltage scale is specified in units of volts per division V div Example If the scale is 2 V div then each major division on the vertical axis represents a 2 V span OFF button The OFF button removes the currently selected waveform from the display MENU button The MENU button activates additional on screen menus for the vertical section Menu based Controls Coupling This selects the channel s input coupling DC AC or Ground e DC Allows both AC and DC signals to get through default e AC Filters out any DC signals so only the AC variation is displayed e Ground Temporarily replaces the waveform with a 0 V flat reference line It is also used to select the channel s input resistance 1 MQ 50 Q e 1 MQ Used for typical voltage measurements default e 50Q Used to match impedance with other 50 Q systems Invert This button inverts the polarity of the selected waveform Bandwidth This controls the oscilloscope bandwidth Full 150 MHz 20 MHz Fine Scale This enables finer adjustment of the vertical
6. ee ee ee ee ee ee ee 13 6 SAVING WAVEFORMS ee ee ee ee ee ee ee ee 14 APPENDIX 1 SPECIFICATIONS ee ee ee ee ee ee ee ee 15 APPENDIX 2 REFERENCES ee ee ee ee ee ee ee ee 15 Tektronix TDS3000 Series Oscilloscope Guide v1 1 Portland State University 1 Introduction This guide provides instructions for operating the Tektronix TDS3000 Series Digital Phosphor Oscilloscopes These are some features of various models in the product line e 100 to 500 MHz bandwidth e Upto5 GS s sample rate e 2or4channels e Full color LCD with graphical user interface e Serial GPIB and LAN I O for data transfer and control e Built in automated measurements 2 Oscilloscope Overview An oscilloscope is an instrument that measures a voltage signal and displays a graph of how the signal varies over time The vertical axis of the graph is the voltage while the horizontal axis is time Important signal characteristics can be extracted from the graph such as the shape and amplitude of the signal the frequency or period of a repetitive waveform and the amount of noise or distortion A probe is used to connect the circuit being tested to the inputs of the oscilloscope Each input or channel can independently measure a signal In a digital oscilloscope an analog to digital converter samples the input voltage signal and converts the analog values to digital form The sampling is performed repeatedly as part of t
7. TRIG button The FORCE TRIG button manually causes a trigger event to occur even if there is no input signal B TRIG button This button provides a B trigger in addition to the existing A trigger MENU button The MENU button activates on screen menus for the trigger section Menu based Controls These are the menu options for edge triggering Source This selects the edge trigger signal source input channel AC line external signal Coupling This allows selection of the coupling DC HF Reject LF Reject Noise Reject Slope This determines whether to trigger on the rising or falling edge of a signal Level This is used to modify the trigger threshold voltage level Tektronix TDS3000 Series Oscilloscope Guide v1 1 Portland State University gt ACQUIRE Section Controls The acquire section controls how signals are acquired and processed Dedicated Controls RUN STOP button This button allows the user to start and stop the continuous waveform acquisition SINGLE SEQ button This enables a single sequence acquisition of a signal after which the acquisition stops he AUTOSET button This button automatically adjusts the VERTICAL HORIZONTAL and TRIGGER controls to acquire a usable display The controls may need further manual adjustment for best results WAVEFORM INTENSITY knob This knob adjusts the intensity of the displayed waveform At maximum intensity the view is like a standard digital oscilloscope At medi
8. allowed to warm up for a while 3 Choose probes that are appropriate for the measurement Each channel requires a separate probe 4 For each channel that will be used a Attach the probe s BNC connector to an input connector on the oscilloscope b If necessary configure the attenuation coupling and input resistance for the channel c Ifthe probe has a built in compensation network then compensate the probe Perform compensation whenever a probe is connected to the oscilloscope for the first time d Connect the probe to the test circuit If you will be working with static sensitive parts then wear a grounding strap before making the connections i Attach the ground clip of the probe to a ground point in the circuit ii Attach the probe tip to the voltage measurement point in the circuit 5 Ifthe test circuit is not turned on yet then apply power to the circuit 6 Adjust the oscilloscope s controls to achieve a stable display of the waveform The AUTOSET button can be used to get a reasonable initial display 7 Voltage measurements are done by counting the number of graticle divisions that a waveform spans in the vertical direction Timing measurements are performed similarly in the horizontal direction The Measure button can be used to automate common signal measurements 13 Tektronix TDS3000 Series Oscilloscope Guide v1 1 Portland State University 6 Saving Waveforms After performing a measurement it
9. ed V div value will be incorrect if the factors do not match e Loading Effect As seen in the schematic diagram the probe and oscilloscope are attached in parallel with the test circuit As a consequence the measured voltage is influenced not only by the circuit s intrinsic characteristics but also by the components of the probe and oscilloscope In particular the effective input resistance and capacitance of the combined probe and oscilloscope system affects the accuracy and fidelity of the voltage measurement Table 1 Typical characteristics of common probes Probe Attenuation Total Input Total Input Best Used For Description Ratio Resistance Capacitance Low to high amplitude 10X b 10 1 1 to 25 pF F prone tome PER DC to high freguency Very low to medium amplitude 1X probe 1 1 1MQ 100 to 200 pF ae Si pana DC to low frequency For most measurements the 10X probe is utilized because its high effective input resistance lessens the load effect on the test circuit and its low input capacitance allows higher frequencies to be measured On the other hand the large attenuation factor makes measurements of very low amplitude signals less accurate If the voltage level of the input signal is tiny then a 1X probe may be a better choice because there is no attenuation through the probe However the 1 MQ input resistance imposes a larger loading effect and the high input capacitance limits the frequency range
10. ellow CH2 blue CH3 purple CH4 green The main graph area is divided into a grid to aid in reading the amplitude and timing of the waveforms Dotted grid lines represent the major divisions on each axis The vertical axis has units of voltage while the horizontal axis has units of time gt Bottom screen and Side screen Menu Buttons The TDS3000 series support an on screen menu for accessing various oscilloscope functions that are not assigned to a dedicated button If an oscilloscope function requires menus then they are displayed on the bottom edge of the LCD screen When a menu option is selected additional submenu options may appear on the right edge of the screen The content of the menus will vary depending on the current function The actual menu buttons are located on the plastic bezel that surrounds the LCD By pressing a button the menu item associated with the button will be selected A dedicated MENU OFF button turns off the on screen menus Tektronix TDS3000 Series Oscilloscope Guide v1 1 Portland State University gt VERTICAL Section Controls The vertical section adjusts the vertical voltage configuration scaling and positioning of the waveform Each channel has its own independent vertical settings Dedicated Controls CH 1 CH 2 CH 3 CH 4 CHANNEL SELECTION buttons All of the available oscilloscope inputs i e channels share a single set of controls The channel selection buttons determine which channel is
11. he time sweep The scope processes the incoming data and displays it on the built in monitor screen as a continuously updated graph of voltage versus time Important specifications of a digital oscilloscope include e Bandwidth Specifies the highest signal frequency that can be accurately measured e Sample rate Determines how often the input signal can be sampled samples per second e Number of channels Determines how many independent signals can be measured simultaneously The front panel of a typical digital oscilloscope has these control sections e Vertical Adjusts the vertical voltage scaling and positioning of the waveform e Horizontal Controls the horizontal time scaling and positioning of the waveform e Trigger Provides a way to stabilize the display of repetitive signals on the screen e Acquisition Controls how the input signal is acquired or sampled 1 The TDS3034B model has a 300 MHz bandwidth 2 5 GS s sampling rate and four analog input channels 2 Tektronix TDS3000 Series Oscilloscope Guide v1 1 Portland State University 3 Instrument Front Panel Side screen Menu function menu buttons controls Oscilloscope General purpose ACQUIRE display knob controls Bottom screen VERTICAL HORIZONTAL menu buttons controls controls Floppy disk Input TRIGGER drive connectors controls Figure 1 Tektronix TDS3000 series front panel Copyright Tektronix Inc gt Power S
12. hen in zoom mode the HORIZONTAL SCALE knob controls the magnification factor while the HORIZONTAL POSITION knob selects the portion of the waveform that should be magnified Tektronix TDS3000 Series Oscilloscope Guide v1 1 Portland State University gt TRIGGER Section Controls To show a stable image of a repeating waveform on the screen the oscilloscope needs to acquire the signal at the same point on the waveform during each sweep This is done by settng a threshold voltage value that when the measured signal crosses the threshold causes the oscilloscope to initiate an acquisition sweep This threshold is called the trigger level The trigger source can be either the input signal itself or an external trigger signal Note If the measured input signal never crosses the threshold because the level was set too high or too low the displayed waveform will be unstable and jitter erratically on the screen The TDS3000 series supports two triggers which are known as the A trigger default and the B trigger optional Dedicated Controls TRIGGER LEVEL knob This knob adjusts the trigger level of the currently selected waveform A horizontal line temporarily appears on the screen to indicate the trigger level The level should be adjusted until the waveform appears stable on the screen SET TO 50 button This button automatically sets the trigger level to 50 of the peak to peak amplitude of the source trigger waveform FORCE
13. is often desirable to save the waveform for later reference Data can be saved as an image file screen capture or as a spreadsheet file actual numeric data Note The oscilloscope automatically generates consecutively numbered file names when saving files Saving as an image file 1 Insert a formatted 3 5 1 44 MB floppy disk into the oscilloscope s disk drive 2 Press the UTILITY button on the front panel 3 Select System from the lower menu Keep pushing the same menu button until Hard Copy is selected The lower menu will change to show only hard copy options 4 Select Format from the lower menu The right submenu will now show a long list of available printers and image file formats Cycle through the options to select the desired format 5 Select Options from the lower menu On the right submenu select either Landscape or Portrait for the orientation of the image 6 Select Ink Saver from the lower menu On the right submenu select either Off to capture the screen colors as is or On to change the background color from black to white 7 Press the MENU OFF button to turn off the menus Once the hard copy options have been set the current screen image can be captured to the floppy disk at any time by pressing the Hard Copy button Saving as a spreadsheet file Insert a formatted 3 5 1 44 MB floppy disk into the oscilloscope s disk drive Press the SAVE RECALL butt
14. on on the front panel Select the channel you want to save by pressing the appropriate Channel Selection button Select To File from the right submenu 1 2 3 4 Select Save Waveform ChX from the lower menu 5 6 To save the data as a spreadsheet file Select Spreadsheet File Format from the right submenu 7 Select Save ChX To Selected File from the right submenu It may take a while for the oscilloscope to finish writing the data to the floppy disk Note Ifthe oscilloscope is connected to a standalone computer via a serial GPIB or LAN connection then the Tektronix OpenChoice Desktop application can be used to transfer the screen image or waveform data directly to the computer 3 Supported image file formats include TIFF PCX BMP EPS and PNG 4 The spreadsheet file is stored in CSV Comma Separated Values text format The resulting file can be imported into a compatible program such as MS Excel or MATLAB 14 Tektronix TDS3000 Series Oscilloscope Guide v1 1 Appendix 1 Specifications Portland State University Table 2 Manufacturer s instrument specifications TDS3034B TDS3052B Bandwidth 300 MHz 500 MHz Channels 4 2 Sample Rate on Each Channel 2 5 GS s 5 GS s Maximum Record Length 10 K points Vertical Resolution 9 bits Vertical Sensitivity div 1 mV to 10V Vertical Accuracy 12 Maximum Input Voltage 1 MO 150 Vrms CAT P
15. osition Range 5 div BW Limit 20 150 MHz 20 150 MHz Input Coupling AC DC GND Input Impedance Selections 1 MQ in parallel with 13 pF or 50 Q Time Base Range 2 ns div to 10 s div 2 ns div to 10 s div Time Base Accuracy 20 ppm Appendix 2 References 1 2 3 4 5 6 ABCs of Probes Primer Tektronix Inc Tektronix TDS3000B Series Data Sheet Tektronix Inc XYZs of Oscilloscopes Primer Tektronix Inc 15 Tektronix TDS3000 amp TDS3000B Operator Training Kit Manual 071 1051 00 Tektronix Inc Tektronix TDS3000B Series Digital Phosphor Oscilloscopes Reference 071 0923 00 Tektronix Inc Tektronix TDS3000B Series Digital Phosphor Oscilloscopes User Manual 071 0957 04 Tektronix
16. scale using the general purpose knob Position This controls the waveform s vertical position using the general purpose knob Offset This adjusts the waveform s vertical offset using the general purpose knob Probe Setup For probes that do not use the TekProbe interface this option allows the probe attenuation factor to be changed using the general purpose knob 1mX to 1kxX full range 1X or 10X typical Tektronix TDS3000 Series Oscilloscope Guide v1 1 Portland State University gt HORIZONTAL Section Controls The horizontal section adjusts the horizontal time scaling and positioning of the waveform All channels share the same horizontal settings Dedicated Controls HORIZONTAL POSITION knob This knob moves the position of the currently selected waveform either left or right on the LCD screen It does not change the horizontal scale HORIZONTAL SCALE knob This knob adjusts the horizontal scale of the currently selected waveform It does not change the horizontal position The horizontal time scale is specified in units of time per division e g ms div Example If the scale is 5 ms div then each major division on the horizontal axis represents 5 ms DELAY button The DELAY button is used to delay signal acquisition relative to the triggering event by using the HORIZONTAL POSITION knob ZOOM button looks like a magnifying glass The ZOOM button magnifies the currently selected waveform along its horizontal axis W
17. um intensity the view simulates an analog oscilloscope MENU button The MENU button activates on screen menus for the acquire section gt MENU Controls The MENU controls activate on screen menus for performing various functions The menu appears at the bottom of the screen while submenu options appear on the right side of the screen MEASURE This button is used to access the oscilloscope s built in automated measurements Some examples include finding the amplitude and frequency of a signal finding the min max values and computing rise and fall times SAVE RECALL This is used to save or recall oscilloscope setups and waveforms to nonvolatile memory or to the floppy disk Measured waveform data can be saved as a Mathcad data file or as a CSV file that can be imported into a spreadsheet Ai QUICKMENU This bypasses standard menus to provide quick access to basic oscilloscope operations CURSOR This is used for making amplitude and time measurements For example vertical or horizontal bars can be superimposed on the screen to mark key points on waveforms DISPLAY This button controls display options such as persistence format and contrast UTILITY This button gives access to system utilities such as setting the hard copy parameters adjusting the system date time and running diagnostics Note The buttons marked with a star are very useful for quickly setting up the oscilloscope Tektronix TDS3000 Series Oscilloscope Guide v1
18. witch The power switch turns the oscilloscope on or off gt Floppy Disk Drive The oscilloscope has a built in 3 5 1 44 MB floppy disk drive Oscilloscope setups and waveform data can be saved to or recalled from a formatted disk that is inserted in the drive gt Hard Copy Button Pushing this button saves the waveform Depending on how the button is configured the waveform can either be stored as a file on a floppy disk or sent to an attached printer P General Purpose Knob The multipurpose knob is used to navigate the screen select an item or change a setting 2 TDS3000 3000A and 3000B models only Later 3000C models have a USB drive port instead 3 Tektronix TDS3000 Series Oscilloscope Guide v1 1 Portland State University gt LCD Screen The screen shows a graph of the signal that is measured on an input channel The oscilloscope provides controls for making individual channels either active waveform is displayed on the screen or inactive waveform is omitted RUN STOP Trigger Status Status coupling Graticle i amp Impedance Divisions DC EE E se EE SE Submenu options Zero Reference Marker Horizontal Scale Vertical Scale A voltage div time div j Trigger EE TM 400MS A Q Settings 0 00000 s 1M 30 Probe Setup 10X idth EIE Position Offset l 0 00 div 0 000 V coupling Invert Bandw DC Off Ful div Menu options Each channel is color coded CH1 y
Download Pdf Manuals
Related Search