Keithley 3930A Service Manual Download

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Summary of Contents for 3930A

Page 1: ...Model 3930A Multifunction Synthesizer Service Manual Contains Operating and Servicing Information...

Page 2: ...NC NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT INDI RECT SPECIAL INCIDENTAL ORCONSEQUENTIAL DAMAGES ARISING OUT OFTHE USE OFITS INSTRUMENTS AND SOFTWARE EVEN IF KEITHLEY INSTRUMENTS INC HA...

Page 3: ...930A Multifunction Synthesizer Service Manual Q 1991 Keithley Instruments Inc Test Instrumentation Group All rights reserved Cleveland Ohio U S A August 1991 First Printing Document Number 3930A 902 0...

Page 4: ...All Keithley product names are trademarks or registered trademarks of Keithley Instruments Inc Other brand and product names are trademarks or registered trader k of their respective holders...

Page 5: ...24V peak are present A good safety practice is to expect that hazardous voltage is present in any unknown cikuit before measuring Inspect the connecting cables and test leads for possible wear cracks...

Page 6: ...rious cirtits in SECTION 2 the Model 3930A Principles of Operation Covers fuse replacement calibration and repair of the instru ment and lists replacement parts SECTION 3 Service Information WARNJNG T...

Page 7: ...RiseandFaLlTimes l 9 SECTION 2 Principles of Operation 2 1 INTRODUCTION 2 l 2 2 BLOCK DIAGRAM 2 l 2 2 1 ControlSection 2 l 2 2 2 Display and Keyboard Section 2 l 2 2 3 TriggerSection 2 l 2 2 4 Synthe...

Page 8: ...placement 3 9 3 4 FAN FILTER CLEANING 3 9 3 5 FCTN OTJTJUMPER 3 9 3 6 RECHARGEABLE BATTERY REPLACEMENT 3 10 3 7 REPAIR 3 10 3 7 1 Factory Service 3 10 3 7 2 PowerSupplyTestPoints 3 10 3 7 3 Board Leve...

Page 9: ...ncy Synthesizer Address Generator Diagram 2 5 Figure 2 4 Address Generator Waveform 2 6 Figure 2 5 Waveform Memory and D A Converter 2 6 SECTION 3 Service Information Figure 3 l CoverRemoval 3 3 Figur...

Page 10: ...riangle Sawtooth Square l 7 Table l 6 Limits for Total Harmonic Distortion l 8 Table l 7 Limits for DC Voltage Accuracy l 9 Table l 8 Limits for DC Level Square and DC Offset Error Sine l 9 Table l 9...

Page 11: ...on and allowed to warm up for at least one hour before beginning the verifi cation procedures If the instrument has been subject to extremes of temperature outside the range specified in the previous...

Page 12: ...s 20V range 0 015 of rdg 3 counts ACV k O 35 of rdg 100counts 20V range lkHk 2OOkHz 0 5 of rdg 2OOkHz 1MHz 0 7 I 1oMHz 3 lo 2oMHz 5 O OlHz 12OMHz time baseaging cl x IO month Vp p measurements lOHz 11...

Page 13: ...Duty Cycle Accuracy Allowable Reading Function Amplitude Frequency ltJ C to 28OC Sine 2ovp p MHZ 999 995lcHz to 1 000005MHz Square XD50 2OVp p 1OOHZ 4 97msec to 5 03msec 1kH Z 497psec to 503psec 5kHz...

Page 14: ...Function Table 1 3 Limits for Amplitude Accuracy Allowable Reading Amplitude Frequency 18OCto 28 0 Sine 7 49vp p 1kHZ 2 6349Vrms to 26613Vrms Square FXD50 3 558W n to 3 782Vrms Triangle 2 0541Vrms to...

Page 15: ...ent 6 Change the frequency setting of the synthesizer ac cording to Table l 4 and verify the subsequent dB readings 7 Program a 1kHz sine function of 3 75Vp p and ver ify that the voltage reading is w...

Page 16: ...1MHz 0 5dB to 0 3dB 1 m l OdB to 0 3dB 3 75vp p 1kTdz 0 65Vnns to 0 676Vrms RJIF 1OkHZ 0 ldB to O ldB 100kHz 0SdB to O ldB 200kHz 0 3dB to 0 3dB 35okHz 0 3dB to 0 3dB 5OOkHz 0 3dB to 0 3dB 7OOkHz 0 3...

Page 17: ...1 03times the REFreading 6 Modify the frequency and function settings of the synthesizer according to Table 1 5 and verify that the corresponding readings are within the specified limits Table 1 5 Li...

Page 18: ...ng is within the limits specified in Table l 6 5 Change the frequen cy setting of the synthesizer ac cording to Table 1 6 and verify the distortion read ings Table l 6 Limits for Total Harmonic Distor...

Page 19: ...ram a 7 49Vp p square wave gated mode Ext 1 trigger source and 90 of phase 4 Setthe DMM to measure DC volts with autoranging and verify that the voltage reading is within the lim its specified in Tabl...

Page 20: ...tion Table I 9 Limits for Rise Fall Times Function Frequency Amplitude Square FXD50 1OOkHZ 3ovp p 3 75vp p 3 74vp p I IAllowable Reading Time lS Cto 28 C Rise Fall E Rise Fdl c 150nsec 150nsec 150nsec...

Page 21: ...on The trigger section generates trigger signals for the burst and gate oscillation modes Circuits in the trigger section include the internal trigger oscillator counter for the burst oscillator the I...

Page 22: ...ation GPIB INTERFACE BLOCK I 1 GPIB I CONTROL BLOCK 9 i SINGL i t START IN L L i HOLD IN i k d MKR OUT f h d r 7 i SYNC OUT i A r 1 i X i IRIVE 0 3 DIGITAL OUT FOR 3933A 0 Rear panel connector Figure2...

Page 23: ...ine triangular and sawtooth waves 2 3 3 Square Wave Generator Squarewaves with fixed 50 duty cycle are generated by applying sine waves to an analog comparator The ana log comparator has acertain amou...

Page 24: ...N 2 Principles of Operation t COMPARATOR 1 I L FUNCTION SELECTOR SQUARE WAVE __ XATOR l i DUTY CYCLE VARIABLE I 7 r MULTIPLIER AM AM ON OFF il5V max OPEN CONTROL DATA we 2 2 Analog SelectionBlockDiagr...

Page 25: ...register overflows at which point the register value returns to all OS The cycle starts again and aramp waveform shown in Figure Z 4 is generated The slope of the ramp is directly proportional to the...

Page 26: ...I Time No of clock cycles Number of clocks or period based on the set outputfrequency d Figure 2 4 AddressGeneratorWaveform Waveform Memory D A Converter Address Analog Waveform output Digital L A Da...

Page 27: ...ble 3 1 Recommended Line Fuses Line Voltage Description 100v 120v 200v 25ov lA 25OV normal blow 5mm x 2om m 1 2A WOV normal blow 5mm x 2Omm Keithley Part No FU 96 2 l LJ 96 l 3 3 CALIBRATION The follo...

Page 28: ...or humidity allow additional time for rable Table 3 2summarizes recommended equipment for cali brating the Model 3930A Similar equipment may be used aslong ascorresponding specifications are compa Tab...

Page 29: ...o avoid s akhing the top cover 2 Remove the four comer screws that secure the bot tom cover then remove the cover 3 Place the instrument right side up 4 Remove the top cover by separating it from the...

Page 30: ...Infomtion Front Panel Side R308 RI 09 RlOl R208 R207 DUTY Cl08 AMP OFS AM OFS AM BAL R 320 SQ R316 R203 R211 R213 SQ AM GAIN DC SPAN DC OFS Rear Panel Side Figure 3 2 Analog Board NP 22022 Calibration...

Page 31: ...ServiceInformation FCTN OUT Enable Disable J401 Rechargeable Battery BT 151 Rear Panel Side I Crystal Oscillator 1 I I 7 t J 0 Front Panel Side Figure 33 Control Board NP 10408 Calibration Adjustment...

Page 32: ...7 Program a DC offset voltage of 15V 8 Verifv that the DMM reading is between 14 996V step 6 to mini e the errors in the 15V and 15V readings 9 Program a DC offset voltage of OV and verify that the D...

Page 33: ...URCE EXT MODE GATE AMPTD 7 49vp p AMzON 5 Adjust R207 AM BAL so that the muliimeter indi cates1OmVor less If an oscilloscope is being used adjust for minimum signal amplitude 6 Select the DCV function...

Page 34: ...ding of 5msec kO 005msec Frequency Accuracy 1 Connect the PM 6654Ccounter A input to the FCTN OUT jack Figure 3 6 2 Setthe counter to the frequency measurement mode 3 Setup the Model 3930A asfollows F...

Page 35: ...the desired position see line cord Figure 3 3for location Setthe jumper to FCTN OUT 2 Remove the filter cover on the rear panel ON to enable FCTN OUT at power on or set it to 3 Remove the filter elem...

Page 36: ...l anew battery taking careto observe polarity 9 After soldering securethe battery to the board using an electronics approved silicone or RTV sealer 10 Install the control board and connect all cablest...

Page 37: ...SECTION3 ServiceInformation 5v TPW GND TP507 Front Panel Side rl0 Ll Figure 3 8 PowerSupply TestPoint Locations 24V TP501 24V TP503 15V TP505 Rear Panel Side GND TP504 TP502 3 11...

Page 38: ...nstrument model number 0 Instrument serial number l Keithley part number l Part description Table 3 5 Replaceable Parts Description Analog circuit board WI 10408A Control circuit board NP 21022B Fan A...

Page 39: ...SECTION3 ServiceInformation Figure 3 9 Exploded View 3 13...

Page 40: ...ng its published specifications when it was shipped from the factory However the typi cal data represents mean values of measurements for eachModel 3930A Thus measured performance of your Model 3930A...

Page 41: ...is 5OQ and 1kHz is the reference frequericy Figure A l Sine WaveAmplitude vs FrequencyCharacteristics Total harmonic distortion W 0 2 10 100 lk 10k 1OOk Frequency Hz Note Amplitudesettingis 3OVpp and...

Page 42: ...0d year tippm year Setting range 84onsto uJooos Display Maximum 6 digits minimum resolution 1Ons Oscillation freouencv is the recinrocal of the settinn wriod kettinns below O lmHz am tnmcated Output C...

Page 43: ...tage s absolute value is less than 15V 1kHz reference frequency OVDC offset AM off 5Of2load SO OmVp pto 3O OVp pamplitude setting when output range is PXD more than 3 OOVpp is effective value measurem...

Page 44: ...of displayed value At lV DC the carrier is suppressed Input Voltage Range 3v to lV Modulation Signal Band DctomokHz Carrier Signal upto1ookHz L Input Impedance 1okQ Connector BNC front panel Frequenc...

Page 45: ...OVto lOV W open circuit Signal OVto lOV Frequency increasing characteristics lOV to OV Frequency decreasing Output Impedance 6OOS2 unbalanced Load impedance lOki2 minimum Connector BNC rear panel Repl...

Page 46: ...form outnut on off 1 I 1Same items as in Memory Contents plus lock on off GPIB address delimiter 1Identical to Memory Modify Format 1Per cursor movement and MODIFY knob Up Down Step Sii 1 1In es or de...

Page 47: ...p p QPlOVp p Q OOmVQ oOv Yl CONT Sweep Related Start frequency Stop frequency Center frequency Span Frequency Marker frequency Sweep time Sweep function QOOOOOkHZ lQ OOOOOOOlCHZ 55000000kHz 000ooo0kHz...

Page 48: ...CR or CR LF panel EOI also sent simultaneously Reception 1CR CR LF CR EOI CR IF EOI or EOI 0 30 selected by numeric keys on the front panel DIOl DIOS NDAC NRPD SRQ Open collector DAV EOI T state Switc...

Page 49: ...OmV 29 9mV to 0 3OmV 3o oov to o oov 8 W to 866V 1865V to 86 6mV 86 5mV to 8 66mV 8 65mV to 0 09mV VPP only 18 8to 1 2 1 3 to 21 2 21 3 to 41 2 41 3 to 80 9 W P only 15mV l l 1 5mV l 10 15opr l 100 15...

Page 50: ...Vp p Hard DCV C Resl 7 3mV 73oJ U 7 3jlv 7 3mV T DC Voltage Accuracy f O 2 of AC amplitude setting p p O l of D voltage setting 8mV SO 296of AC amplitude setting p p 0 6 of D voltage setting 08mV SO 2...

Page 51: ...P Ill 0 a 7 Figure B l Outer Dimensionsoffhe Model 3930A...

Page 52: ...ay Contrast 3 9 E Environmental Conditions l 1 3 2 F Factory Service 3 10 Fan Filter Cleaning 3 9 FCTN Out Jumper 3 9 Frequency Accuracy 3 8 Frequency and Duty Cycle Accuracy 1 2 Frequency Response 34...

Page 53: ...Level 3 6 Square Wave JX Level 3 8 Square Wave Duty Cycle 3 8 Square Wave Generator 23 Synthesizer Operating Principles 2 5 Synthesizer Section 2 l T Total Harmonic Distortion l 8 Trigger Section 2 l...

Page 54: ...pecify D Batteries and fuses are OK a Checked all cables a Calibration only a Data required u Certificate of calibration required attach any additional sheets as necessary Show a block diagram of your...

Page 55: ...Test Instrumentation Group Keithley Instruments Inc 28775 Aurora Road Cleveland Ohio 44139 Printed in the U S A...

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