Agilent Technologies 33120A manual

Servi ce G uide Publication Number 33120-90017 ( order as 33120-90104 manual se t ) Edition 6, March 2002 © Copyright Agilent Technologies , Inc. 1994-2002 For Safety i nfor matio n, War ranti es, and R egulat ory in form atio n, s e e t h e last page in this manual . Agilent 3312 0A 15 MHz Function / Arbitrary Waveform Genera tor Cover Page for W[...]

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The Agilent Technologies 33120A is a high-performance 15 MHz synthesize d function generator with built-in arbitrary wavefo rm capability. Its combination of bench-top and syste m features makes this function genera tor a versatile solution for your testing r equirements now and in the futur e. Convenie nt bench-top fea tures  10 standard wavefo[...]

The Front Panel at a Glance 1 Function / Modulation keys 2 Menu operation keys 3 Waveform m o d i f y keys 4 Single / Internal Trigger key ( Burst and Sweep only) 5 Recall / Store i nstrument state key 6 Enter Number key 7 Shift / Local key 8 Enter Number “units” keys 2[...]

Front-Panel Number Entry Increm ents the flashing digit. Decrem ents the flashing digit. Moves the flashing di git to the right . Moves the flashing digit to the le ft . Use “Enter” for those operat ions that do not require units to be speci fied (AM Level, Offset, % Duty, and Store/Recall State). You can enter numbers from the front-panel usin[...]

The Front-Panel Menu at a Glance T he menu is organized in a top-down tree structure with thr ee levels. A: MODulation MENU 1: AM SHAPE 2: AM SOURCE 3: F M SHAPE 4: BURST CNT 5: BURST RATE 6: BURST PHAS 7: BURST SRC 8: FSK FREQ 9: FSK RATE 10: FSK SRC B: SWP (Sweep) MENU 1: START F 2: STOP F 3: SWP TIM E 4: SWP MODE C: EDIT MENU * 1: NEW ARB [ 2: P[...]

Display Annunciators Adrs Rmt Trig AM FM Ext FSK Burst Swp ERROR Offset Shift Num Arb Function generator is addressed to listen or talk over a remote interface. Function generator is in remote mode (remote interface). Function generator is waiting f or a single trigger or external trigger (Burst, Sweep). AM modulation is enabl ed. FM modulation is [...]

The Rear Pa nel at a Gla nce 1 Chassis ground 2 Power-l ine fuse-holder assembly 3 Power-l ine voltage setting 4 AM modulation input terminal 5 Ext ernal Trigger / FSK / Burst modulation input terminal 6 GPIB (IEEE-488) i nterface connector 7 RS-232 interface connector Use the front-panel Input / Output Menu to:  Select the GPIB or RS-232 interf[...]

In This Book Spe cific ation s Chapter 1 lists th e function generator’s sp ecifications and descri bes how to interpre t these specific ations. Quick St art Chapter 2 prepares the function ge nerator for use and helps you get familiar with a few o f its front-panel features. Front-Pane l Menu Operation Chapter 3 i ntroduces you to the front -pan[...]

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Contents Contents Chapte r 1 Specifi cations Chap ter 2 Qu ick Sta rt To prep are the function ge nerator for us e 21 If the function ge nerator does n ot turn on 22 To ad just th e carr ying h andle 24 To set the output frequen cy 25 To set the ou tput amplitude 26 To set a dc offset voltag e 27 To set the duty cycle 28 To output a stored arbitrar[...]

Chapte r 4 Calibratio n Procedures (contin ued) Calibration Security Code 64 Calibration Count 66 Calibration Message 66 General C alibration/A djustmen t Procedur e 67 Aborting a Calibration in Progress 69 Frequenc y and Burst Rate Ad justment 69 Function Gain and Linearity Adjustme nt 70 AC Amplitude Adju stment (High-Z ) 70 Modulation A djustmen[...]

Contents Chapter 6 Service Operating Checklist 103 Types of Service Available 104 Repackaging for Shipment 105 Cleaning 105 Electrostatic Discha rge (ESD) P recautions 106 Surface Mount Repair 106 To Replace the Power-Lin e Fuse 107 To Replace the Output Prote ction Fuse (F801) 107 Troublesho oting Hints 108 Self -Test Pr ocedures 110 Chapt er 7 Re[...]

Contents 12[...]

1 Spec ificat ions 1[...]

WAVEFORMS Standard Waveforms: Arbitrary Waveforms: Waveform Length: Amplitude Resolution: Sample Rat e: Non-Volatile Memory: Sine, Square, Triangle, Ramp, Noise, DC vol ts, Sine(x)/x, Negative Ramp, Exponential Rise, Exponential Fall, Cardiac 8 to 16,000 points 12 bits (including si gn) 40 MSa / sec Four 16,000-point waveforms FREQUENCY CHARACTERIS[...]

MODULATION CHARACTERISTICS SYSTEM CHARACTERISTICS AM Modu lation Carrier -3 dB F req: Modulation: Frequency: Depth: Source: FM Modu lation Modulation: Frequency: Peak Deviation: Source: Burst Modulation Carrier Frequency: Count: Start Phase: Internal Rate: Gate Source: Trigger Source: FSK Modu lation Frequency Range: Inte rnal Ra te: Source: 10 MHz[...]

GENERAL SPECIFICATIONS Power Su pply: (1) Power -Line Freque ncy: Power Installation: Power Consu mpti on: Operating E nvironment: Storage Envi ronment: State Storag e Memory: Dimensions (W x H x D) Bench Top: Rack Mount: Weight: 100V / 120V / 220V / 240V 10% (switch selectable) 50 Hz to 60 Hz 10% and 400 Hz 10%. Automati cally sensed at power-on. [...]

PRODUCT DIMENSIONS TOP All di mensio ns are shown in mi llimet ers. 1 Chapter 1 Specifications Agilent 33120A Function Generator 17[...]

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2 Quic k Start 2[...]

Quick Start One of the first things y ou will want to do with your function gene rator is to become acquainted with its front pan el. We have wr itten the exercises in this chapter to prepare the fu nction generator for use and help yo u get familiar with some of the front-panel operations. The fron t panel has two r ows of keys to select vario us [...]

To prepare the function generator for use The follow ing st eps he lp yo u verif y tha t the fu nction genera tor is ready fo r use. 1 Check the list of supplied items. Verify that you have rec eived t he follow ing items with yo ur func tion gen erator . If any thing is mi ssing , cont act yo ur neare st Ag ilen t Technologies Sales Office. One po[...]

If the function generator does not turn on Use the follow ing steps to help solve problems you might expe rience when turning on the function gene rator. If you need m ore help, see chapte r 6 for instructions on returning th e function generator to Agilent for service. 1 Ve rify that there is ac power to the functi on gene rator. First, ve rify th[...]

Verify that the correct line voltage is selected and the power-line fuse is good. 1 Remove the power cord . Remove the fuse-holder assembly from the rear panel. 2 Remov e the line-vo ltage selec tor from the assembly. 3 Rotate the line-voltag e selector until the correct voltage appears in the window. 4 Replac e the fuse- holder a ssembl y in the r[...]

To adjust the carrying handle To adju st the position , grasp the handle by th e sides an d pu ll outwa rd . Then, rotate the handle to the desi red position. Bench-top viewing positions Carrying position Chapter 2 Quick Start To adjust the carrying h andle 24[...]

To set the output frequency At power-on, the f unction generator outputs a s ine wave at 1 kHz with an amplitude of 100 mV peak-to-peak (into a 50 W termination). The foll owing s teps sho w you how to ch ange the frequen cy to 1.2 MHz. Freq 1 E nab le the freq uency modify mode. The d ispla yed fre quenc y is eith er the powe r-on value o r the p [...]

To set the output amplitude At power-on, the f unction generator outpu ts a sine wave with an amplitude of 100 mV peak-to-pe ak (into a 50 W termination). The foll owing s teps sho w you how to ch ange the amplitud e to 50 mVrms. Ampl 1 E nab le the a mplitude modify mode. The displayed amplitude is either the power-on value or the prev ious amplit[...]

To set a dc offset voltage At power-on, the f unction generator outputs a s ine wave with a dc off set voltage of 0 v olts (into a 50 W termination). The foll owing s teps sho w you how to change the offset to – 1.5 mVdc. Offs et 1 E nab le the o ffset modify mode. The dis played offs et voltage is either the po wer-on value or the p revious offs[...]

To set the duty cycle Applies only to square waves. At power-on, the duty cycle for square waves is 50%. You can adjust the duty cycle for a s quare waveform from 20% to 80%, in in crements of 1% (for frequenci es above 5 MHz, the range is 40 % to 6 0%). The following steps show you how to change the dut y cycle to 45 %. 1 Select the square wa ve f[...]

To output a stored arbitrary waveform There are five built-in arbitrary waveforms stored in non-volatile memory for you r use. Yo u can out put th ese wave forms dir ectly f rom non- volatil e memory. The followin g step s show you how to outpu t an “ex ponential rise” waveform fr om memory. Shift Arb List 1 D ispl ay the list of arbitr ary wa [...]

To output a dc voltage In addition to ge nerating wavefo rms, you can also o utput a dc voltage in the rang e  5 Vdc (into a 50 W termination). The fo llowin g steps s how you how to output +155 mVd c. 1 Press the key and hold it down for more tha n 2 seconds . To enter the dc voltage mode, press the Offset key or any k ey in the top row of fu n[...]

To store the instrument state You can store up to three different instrumen t states in non-volatile memory. This enables you to recall the entire instrument configuration with just a few key pres ses fro m the fr ont panel . The fol lowing steps show you how to store a nd reca ll a st ate. 1 Set up the function generator t o the desired config ura[...]

To verify that the sta te was store d properly, you can turn the power o ff befo re reca lling t he stat e. Recall 5 Recall the st ored i nstr ument state. To recall th e stored state, yo u must use the same memo ry locati on used previously to store the state . Use the up an d down arrow keys to change the disp layed stor age location. RECALL 2 To[...]

To rack mount the function generator You ca n mount t he func tion ge nerator i n a stan dard 19 -inch r ack cabinet using one of three o ptional kits available. Instructions and moun ting hardwa re are i ncluded with ea ch rack -mou nting ki t. Any Agilent System II instr ument of the same size can be rack-mounted beside the 33120A F unction Gener[...]

To rack mount a single instrument, order adapter kit 5063-9240. To rack mount two instruments side -by-side, order lock-link kit 5061-9694 and flange kit 5063-9212. To install one or two instru ments in a sliding support shelf, order shelf 5063-9255, and slide kit 1494-0015 (for a single instrume nt, also order filler panel 5002-3999). Chapter 2 Qu[...]

3 Front-Panel Menu Operation 3[...]

Front-Panel Menu Operation By now you shou ld be familiar with some of the basic features of th e front panel. Chapter 2 shows you ho w to prepare the function gene rator for use and describes a few of the front-panel features. If you are not familiar with t his in format ion, we recomm end th at you rea d chapter 2, “Quick St art,” starting on[...]

Front-panel menu reference A: MODulation MENU 1: AM SHAPE Õ 2: AM SOURCE Õ 3: FM SHAPE Õ 4: BURST CNT Õ 5: BURST RATE Õ Õ 6: BURST PHAS Õ 7: BURST SRC Õ 8: FSK FREQ Õ 9: FSK RATE Õ 10: FSK SRC 1: AM SHAPE Selects the shape of t he AM modulating waveform. 2: AM SOURCE Enables or disabl es the internal AM modulating source. 3: FM SHAPE Sele[...]

D: SYSt em MENU 1: O UT TERM Õ 2: PO WER ON Õ 3: ERROR Õ 4: TEST Õ 5: COMMA Õ 6:REVI SION 1: OUT TERM Selects the output terminat ion (50 or high impedance). 2: POWER ON Enables or disables automatic power-up in power-down state “0”. 3: ERROR Retrieves errors from the error queue (up to 20 errors). 4: TEST Performs a complete sel f-test. 5[...]

A front-panel menu tutorial This se ction is a step- by-step tutor ial which shows y ou how to us e the front-panel me nu. We recomm end that you spe nd a few minutes w ith this tutorial to get c omfortable with the s tructure and operation of the menu before attem pting verification, calibration, o r adjustments. The men u is organized in a top- d[...]

Messages Displayed During Menu Use TOP OF ME NU You pressed ¾ while on the “ MENUS ” level; this is the top level of the menu and you cannot go any higher. To turn off the menu, pres s Shift Menu On /Off . To move a cross the cho ices on a level, pr ess < or > . To move down a level, press ¿ . MENUS You are on the “ MENUS ” level. P[...]

Menu Example 1 The following steps show you how to turn on the menu , move up and down between levels, move across the choices on each level, and turn off the menu. In this example, you wi ll restore th e function generator to the power- on defa ult state. Th is proc edure i s recomme nded bef ore per forming the v erifi catio n pro cedu res in c h[...]

5 Move do wn a leve l to the “ PARAMETER ” choi ces. The first parameter c hoice is “ DEFAULT ” for the POWER ON command (“ DEFAULT ” is the factory setting and is s tored in non-volatile memory). DEFAULT > 6 Move ac ross to the “LAST STATE” choice. 1 Ther e are tw o parame ter ch oices for POWER ON . LAST STATE Enter 7 S ave t h[...]

Menu Example 2 Some commands in t he menu re quire that you enter a n umeric parameter value. The follow ing steps show you how to enter a number in the menu. Fo r this examp le, yo u will c hange t he out put am plitu de. Ampl 1 Select ampl itude adj ustment The fu nction generator d isplays the curren t output amplitu de. 1 0 0.0 mVPP < 2 M ov[...]

To select the output termination The functi on gene rator h as a fi xed out put imp edanc e of 50 oh m s o n the OUTPU T te rmina l. You c an spe cify w hethe r you are terminating the output into a 50 W load or an open circu it. Incorrect impedan ce matching between t he source and loa d will r esult in an outp ut amplit ude or dc offset which doe[...]

To output a modulated waveform A modulated waveform consists of a carrie r and a modul ating wavefor m. In AM (amplitude modulation), the amplitude of the carrier is v aried by the amplitud e of the mo dulating wav eform. For th is exam ple, you wil l output an AM wavefor m with 80% modulation depth. Th e carrier will be a 5 kHz sine wave and the m[...]

4 Move do wn a level verify tha t “ SINE ” is selected. For th e modulat ing wavef orm, you c an select a sine, squ are, tria ngle, ramp, noise, or arbitrary waveform. For th is examp le, you wil l modulate the carr ier with a s ine wave form. Notice that the AM annunci ator fla shes, indicating that the d isplayed pa rameter is for AM . SINE E[...]

To unsecure the function generator for calibration The funct ion ge nerato r can u se a ca libra tion s ecuri ty co de to p revent unaut hori zed or a ccide ntal c alibra tion. T his pr ocedur e shows you h ow to unsecure the func tion ge nerator for calibration . Shift 1 Turn on the menu. Menu On/Off A : MOD MENU < 2 Move ac ross to the CAL MEN[...]

4 M ove d own t o th e “par amet ers” level. ^000000:CODE 0 3 3 1 2 0 5 Unsecure the functio n generator by e ntering the securit y code. ENTER ^033120:CODE The security code is s et to “HP33120” when the function gen erator is ship ped fro m the fa ctory. T he se curity co de is s tored i n non-vol atile memory and does not change when the[...]

4 Calibrat ion Procedures 4[...]

Calibration Procedures This ch apter con tains proc edures for veri fication of the function generator’s performance and adjustment (calibration). The chapter is divided into the follow ing sections:  Agilent Calibration Services . . . . . . . . . . . . . . 51  Calibration Interval . . . . . . . . . . . . . . . . . . . 51  Time Required [...]

Closed-Case Electronic Calibration T he func tion ge nerat or fea tures closed -case electron ic calibration s ince no internal m echanical adjustments are required fo r normal calibration. The function generator calculates correc tion factors bas ed upon the input refer ence value y ou set. The new correction factors are stored in non-volatile mem[...]

Automating Calibratio n Procedures You can autom ate the complete verification and ad justment pro cedures outlined in this chapter if you have access to p rogrammable test equi pmen t. You c an progr am the instru ment confi guratio ns spec ifie d for each test ov er the remote inte rface. You can then en ter readback verification data into a test[...]

Test Consid erations To ensure proper instrument operation, verify that you have selected the correct power line vo ltage prior to atte mpting any test pro cedure in this chapter. See page 22 in chapter 2 for more information. For op timum perfo rmance, all tes t procedur es should c omply wi th the following recommendations:  Verify the f uncti[...]

Perform ance Verifica tion Tests The pe rformance v erification tes ts use the function ge nerator’s specifications liste d in chapter 1, “Specif ications,” starting on page 13. You can perf orm fo ur diffe rent le vels o f perfo rmance ve rifi cation te sts:  Self -Test A serie s of internal verification tests that give a high confidence [...]

Quick Perf ormance Che ck The quick performance check is a combination of internal self-test and an abbreviated performance test (specified by the letter Q in t he performance verification tests). This te st provides a sim ple method to ach ieve high confidence in the function generator’s ability to functionally operate and meet s pecifications .[...]

Frequency Verifi cation This tes t verifies the frequency accuracy of the two sources in the funct ion gene rator. All o utput f requenc ies are de rived fr om a singl e generat ed fre quency, a nd only one fre quency p oint is c hecked. The se cond test verif ies the burst rate f requency. Set the f unction generator fo r each output indicate d in[...]

DC Function Offset Verification This test ve rifies the DC offset and DC outp ut specifications. Set the f unction generator fo r each output indicate d in the table below. Use a DM M to measure the f unction generator dc V output. Compare the measured results to th e test limits show n in the table. This is a HIGH Z output termination tes t. Agil [...]

Agilen t 33120A Measu rement Functi on OU T T ER M 1 Am pl Freq Nominal Error Q Sine wav e HIGH Z 7 .0 Vr ms 1. 00 k Hz 7.0 Vrm s  0. 070 Vrms Sine wav e HIGH Z 5 .7 Vr ms 1. 00 k Hz 5.7 Vrm s  0. 057 Vrms Sine wav e HIGH Z 5 .5 Vr ms 1. 00 k Hz 5.5 Vrm s  0. 055 Vrms Sine wav e HIGH Z 4 .4 Vr ms 1. 00 k Hz 4.4 Vrm s  0. 044 Vrms Sine w[...]

Install the 50 W feedthrough load be tween the DM M and the function generator output. Set the fu nction generator f or each output indicated in the table on the next page. Us e a DMM to me asure the ACrms ou tput voltage of th e function generator. Com pare the measured results to the test limits show n in the table. This is a 50 W output terminat[...]

Amplitude Flatness Verification This test verifies th e output amplitud e flatness spec ificati on at selec ted frequencies. If you use a TVC (recom mended) or a wide band ACrms voltmet er (wi th a 50 W feed through load), perform this procedure as describ ed. If you are us ing a measuremen t device that requir es a transfer measurement (for exampl[...]

AM Modulation Depth Verification This test ve rifies the modulation depth specification. Select each fu nction generator o utput in the table below. Us e a DMM to measure the function generator ACrms o utput voltage. Compare th e measured results to th e test limits show n in the table. This is a HIGH Z output termination test. Agilen t 33120A Meas[...]

Optional Performance Verification Tests Thes e tests are not intended to be perfo rmed with every calibration . They are provided as an aid for v erifying additiona l instrumen t specifica tions . Square Wave Du ty Cycle Verification This tes t verifies the duty cycle spe cification of the squar ewave outpu t. Select ea ch funct ion gener ator out [...]

Distorti on Verification This test checks th e Harmonic Distortion at selected frequencies and harmonics. This tes t requires the use of a spectrum analyzer with dyna mic ra nge, fre quenc y range, and res olut ion band width a dequa te for the me asurement. Select each fu nction generator o utput in the table below. Us e a spectrum analyzer connec[...]

Calibr ation Securi ty Code This feat ure allo ws yo u to en ter a se curity code (elec tronic key) to preven t accidental or unauthorized calibrations of th e function gener ator. When you f irst rece ive your function generato r, it is secure d. Before yo u can adjust calibration constants you must unsecure the function generator by en tering the[...]

To Unsecure the Func tion Generato r Without the Sec urity Code To unsec ure the function gen erator without the co rrect security code , follow th e steps be low. A pr ocedure to unsecu re the fu nction ge nerator is given on page 47. Also se e “Electrostatic Discharge (ESD) Precautions” in chapter 6 before beginning this procedure. WARNING SH[...]

Calibration Count The calibration count feature provid es an independent “se rialization” of your calibrations. Yo u can determine the n umber of times th at your function generator has bee n calibrated. By monitoring the calibration count , you can d etermin e whethe r an una uthor ized calib ration has bee n performe d. Sinc e the value incre[...]

General Ca libratio n/Ad justment Procedure The adjustment proced ures described in chapter 4 use the CAL ME NU to generate and s et internal calibration constants. T he general menu procedure is the same f or all calibration setups. The foll owin g exampl e demonstrates making the Frequenc y and Burst Rate adjustments. Shift 1 Turn on the menu. Me[...]

< > 7 Move t he fla shin g cur sor o ver th e di git to b e ed ited . 1 ^ 8 Chang e the v alue in the d ispla y to ma tch t he me asured frequ ency. 1.000,00 4 0KHz Enter 9 C alcula te and save th e new value . CALIBRATING 10 Perform the n ext ad just ment proc edure. The se tup number and function generator output is automatically set fo r t[...]

Aborting a Cali bration in Prog ress Sometimes it may be necessary to abort a calibration after the procedure has already been initiated. Y ou can abort a calibration at any time by pres sing an y fro nt-pan el key ( exce pt Shift-Ca ncel ) . When perfor ming a cal ibrati on fro m the rem ote i nterf ace, you ca n abo rt a ca librat ion b y issuing[...]

Function Gain and Linearity Adjustment The function generator stor es six calibration co nstants related to f unction gain and li nearit y. The c onstant s are c alcul ated from th e adju stment value e ntere d. If the calib ratio n proce dure is ab orted b efore all set up step s have been completed, n o calibration co nstants a re stored. 1 Use a[...]

Nominal Output SETUP FREQUENCY AMPLITUDE Adjustment f or: 8 1 kHz 5.5 V rms 2 dB Ou tput At tenuat or 9 1 kHz 4.4 V rms 4 dB Ou tput At tenuat or 10 1 kHz 3.5 V rms 6 dB Outp ut Atte nuator 11 1 kHz 2.8 V rms 8 dB Outp ut Atte nuator 12 1 kHz 2.2 V rms 10 d B Outp ut Atte nuator 13 1 kHz 1.7 V rms 12 d B Outp ut Atte nuator 14 1 kHz 1.4 V rms 14 d [...]

Modulation Adjustment The func tion generator stor es three calibration constants related to amplitud e modulation depth. The c onstants are c alculated from the adjustment va lue entered. If t he cali bratio n pro cedure is aborte d befo re all setup steps have be en co mplet ed, n o calib rati on co nstan ts are st ored. 1 Use a DM M to measure t[...]

AC Amplitude Adjustment (50 W ) 1 The function generator stor es 16 calibration constants related to 50 W outp ut. T he cons tants are ca lcula ted f rom the adjus tmen t valu e ente red. The calibration constants are stored following comp letion of setup 49 and the calibration procedure may be aborted afte r that point. No calibration constants ar[...]

4 Use the DM M to measure th e function generator ACrms output vo ltage for each setu p in the table on the nex t page. These adjustments use the 50 W load and cable measured in ste p 2 and connected as shown below. Chapter 4 Calibration Procedures AC Amplitude Adju stment (50 W ) 74[...]

Nominal Output SETUP FREQUENCY AMPLITUDE Adjustment for: 34 1 kHz 3.5 Vrms 0 d B Output Atte nuator 35 1 kHz 2.8 Vrms 2 d B Output Atte nuator 36 1 kHz 2.23 Vrm s 4 dB Ou tput A ttenu ator 37 1 kHz 1.77 Vrm s 6 dB Ou tput A ttenu ator 38 1 kHz 1.41 Vrm s 8 dB Ou tput A ttenu ator 39 1 kHz 1.12 Vrms 10 dB Outp ut Atte nuator 40 1 kHz .887 Vrms 12 dB[...]

DC Output Adjustment The func tion generator s tores nine calibratio n constants related to DC volt s out put. The con stan ts are c alculat ed fr om the ad justme nt va lue entered. The calibration constants are sto red following completion of setup 59. No calibra tion con stants ar e stor ed if the proced ures ar e aborted at an y other s etup. 1[...]

Duty Cycle Adjustment The func tion generator s tores two calibration constants related to squarewa ve offset an d two calibration constan ts related to squ arewave duty cy cle. The con stants are calcu lated from the adjustm ent value entered. The calibration constants are sto red following completion of setup 63. No calibra tion con stants ar e s[...]

This pr ocedure c an be perf ormed with one of th ree type s of me asuremen t device; a broadband ACrms voltmeter, a power meter, or a thermal voltage c onverter. T he proced ure diff ers sligh tly dependin g upon the ty pe of measurement device used. These adjustments us a 50 W o utput te rmination . 1 Use a DMM to measure the ACrms output volt ag[...]

3 For each setup in th e table below, use the CALIBRATE command to change the dis played amplitude to m atch the measu red amplitude. Nominal Output SETUP FREQUENCY AMPLITUDE Adju stment for: 65 100 k Hz 3.0 V rms 100 kHz amplit ude fl atness 66 500 k Hz 3.0 V rms 500 kHz amplit ude fl atness 67 1 MH z 3.0 V rms 1 MHz am plitud e flat ness 68 3 MH [...]

Output Ampl ifier Adj ustment (Optiona l) This adjustmen t procedure should only be performed following repairs to the Output Amplifier circuitry. The adju stment improves the high frequency performance of the Output Amplifier. 1 Remove the function generator power and cover as des cribed on page 130. 2 Use a DMM to measure the ACrms voltage across[...]

Error Messages The following tables are abbreviated lists of function generator’s error messages. T hey are intended to include errors which are likely to be encou ntered d uring the proc edures describ ed in thi s chapte r. Fo r a mor e complete list of error me ssages and desc ripti ons, see chapte r 5 in the Agilent 33120A User’s Guide . Sys[...]

Calibration Error Message s Error Error M essage 701 Cal se curity di sabled by jump er 702 Cal se cured 703 Inval id secure code 704 Secure code to o long 705 Cal abort ed 706 Cal va lue out of range 707 Cal sign al measu rement ou t of range 708 Fla tness ca l failed 709 Cannot ca libra te freq uency w hile ext ernal ly locke d (Optio n 001) 760 [...]

5 Theory of Operation 5[...]

Theory of Operation This chapter is organized to p rovide descriptions of the circuitry contained on the schematics shown in chapter 8. A block diagram overview is p rovided followed by more detailed descriptions of the circuitry containe d in the schematics chapter.  Block Diagram Overview . . . . . . . . . . . . . . . . 85  Output Attenuato[...]

Block Diagram Overview This discussion per tains to the block diagram shown on page 129. The fu nction function ge nerator’s circuitr y is divide d into two maj or bloc ks: th e floating se ction and the earth (g round) re fere nce sec tion . All signal generation, control, and display functions are con tained in the flo ating se ction. This sect[...]

Output Attenuator Block 8 on block diagram page 129; Schematic on page 138. The Output Attenuato r provides 0 to 30 dB of signal attenuation betwee n the output amplifier section and the output BNC connector. Output signal levels are controlled by combining coarse amp litude control from the outp ut atte nuator sectio n and p re-atte nuator sectio [...]

Output Ampl ifier Block 7 on block diagram page 129; Schematic on page 137. The outpu t amplifier drive s the function gen erator’s signal output through the outp ut attenuator section. The output amplifier exhibits an approximate 35 MHz bandwidth and 1000 V/ m s slew ra te. A C signa ls originating from the DAC+ and DAC- signal paths are combine[...]

The block diagram shows four basic stages: dc amplifier, input differential amplifier, gain, and power output. The amp lifier’s input differential amplifier stage and gain stage are s ymmetrical. The +AMP_IN and -AMP_IN inputs are both amplified through compleme ntary amplifiers whose outputs are s ummed to gether at the inpu t of the powe r outp[...]

AM Modulation Bloc ks 3 and 6 on block diagram page 12 9; Schem atics on pages 13 6 and 133. Amplitude modulation is performed by analog multiplier U603 combining the AM_IN and +FUNCTION a nd -FUNCTION signals. Modulation depths from 0% to 120% are set by varying the s ignal at AM_IN. When the am plitude mo dulation func tion is selecte d, the outp[...]

Pre-attenuator Block 6 on block diagram page 129; Schematic on page 136. All signals, e xcept square waves, pas s through the preatten uator. The preatte nuator multiplexes eight resistive 2 d B attenuators to provid e attenuation from 0 dB to 14 d B in 2 dB steps. The 0 d B, 2 dB, and 4 dB attenuation ste ps are used fo r level settings be tween t[...]

Transistors Q 601 and Q602 buffer the output of the sine wa ve anti-alias filter to the input of comparator U620. Square wa ve duty cycles are controlled by the SQ_SYM input on th e invert ing input of the compar ator. The squarewave o utputs of U620 are amplified by variable gain amplifiers Q603 and Q604. The amplifier gain output level is control[...]

Filters Block 5 on block diagram page 129; Schematic on page 135. The ou tput of the Wav eform DAC passes through one o f two anti-alias filters. A 17 MHz 9th order elliptical filter is used for the sine wave and squar e wave output function s. A 10 M Hz 7t h order Besse l filte r is us ed for fi ltering all othe r output funct ions, in cluding a l[...]

Waveform DAC/Amplitud e Leveling/Waveform RAM Block 4 on block diagram page 129; Schematic on page 134. The Waveform DAC, U407, converts 12-bit digital data from waveform RAM’s U404 and U405 into positive and negative analog voltages. A simplified diagram of the Waveform DAC circuitry is shown below. The preattenua tor, filters, and associ ated c[...]

The Waveform DAC voltage referen ce is driven by U410B. This reference controls the mag nitude of the nom inal 0 to -40 mA DAC outpu t current. The reference le vel is varied to produce 0 to -2 dB fine amplitude level control via dc signal AMP_CTL and  2 dB of dynamic amplitude flatness correction f or static and sw ept frequency operation via f[...]

Direct Di gital Synthesis ( DDS ASIC) Block 2 on block diagram page 129; Schematic on page 132. The DDS ASIC, U206, controls the WA ( waveform address) and MA (modulation addres s) busses. The wavef orm address is used by the waveform RAMs U404 and U405. T he modulation data bus is used by the modulation RAM U205. The DDS ASIC is comprised of sever[...]

System DACs Block 3 on block diagram page 129; Schematic on page 133. All output amplitudes are derived from the internal voltage reference of System DAC U303. The sy stem dac track/hold amplifier outputs are used to provide controllable bias v oltages to various analog circuits including AM modulation depth, square wave amplitud e, square wave dut[...]

Floating L ogic Block 1 on bloc k diagr am page 129; Sc hematic on pag e 131. The floating l ogic controls the operat i on of the ent ire function function generat or. All outp ut funct ions and bus c ommand int erpreta tion is performed by the m ain CPU, U102. The front panel and earth referenced logic operate as slaves to U1 02. The main CPU port[...]

The main CPU, U102, communicates with the e arth referenced logic through an optically isolated asynchronous serial data link. U101 isolates the incomin g data (OG_ RXD*) from t he earth referenc ed logic. Si milarly, U901 isolates the data from U102 (OG_TXD) to the earth ref erence logic. Data is sent in an 11-bit frame at a rate of 187.5 k bits/s[...]

The ac mains are connected by a fuse d power entry module, P1. This m odule incorpo rates the functio ns of mains connec tion, on/of f switching, fusing, and line voltage selection (100/120/220 (230)/240). The line voltage se lection function of module P1 selects which primary windi ng of p ower t ransf ormer T1 is en ergize d. The tran sformer sec[...]

Display and Keyboard Block 11 on block diagram page 129; Schematic on page 141. The front pa nel c ircuits cons ist o f vacu um fl uores cent di splay contr ol, disp lay high voltage drivers , and key board s canning. C omm unicatio n between the front panel and f loating logic circuits is accom plished through a 4-wire bi-directional serial interf[...]

6 Service 6[...]

Service This chapter discusses th e procedures involved for returning a failed funct ion generat or to Agilent for service or repair . Subjects cove red include the follow ing:  Operating Checklist . . . . . . . . . . . . . . . . . . . 103  Types of Service Available . . . . . . . . . . . . . . . 104  Repackaging for Shipment . . . . . . .[...]

Operating Checklist Before r eturning yo ur func tion gene rator to Agile nt for serv ice or repair , check the following item s: Is the function g enerator inopera tive? Verify that the ac power cord is connected to the funct ion generator. Veri fy that the front-p anel Po wer s witch is depres sed. Verify that the power-line fuse is good (se e pa[...]

Types of Service Avail able If your funct ion gene rator fa ils duri ng the war rant y period (within three years of original purchase), Agilent will replace or repair it free of charge. After your warranty expires, Agilent will repair or replace it at a competitive price. The stan dard repair process is “w hole unit exchange”. The replacement [...]

Repackagi ng for Ship ment If the unit is to be shipped to Ag ile nt for service or repair, be sure to:  Attach a tag to the unit iden tifying the owne r and indicating the required service or repair. Include the instrument model number and your full serial number.  Place the unit in its original container with appropriate packaging material.[...]

Electrostatic Discharge (ESD) Precautions Almost all el ectrical components can be da maged by ele ctrostatic disch arge ( ESD ) during han dling. Component damage can oc cur at electrostatic discharge voltages as low as 50 volts. The following guideline s will help prevent ESD damage when se rvicin g the function gen erator or any electron ic devi[...]

To Replac e the Power-Li ne Fuse The po wer-line fuse is located w ithin the function generator’s fus e-holder assembly on the rear panel ( see page 22 ). The function generator i s shi ppe d from the fac tory with a 50 0 mAT slow-blow fuse installed ( part n umb er 2110-0458). This is the correct fuse for all line voltages. To Replace the Output[...]

Troubleshooting Hints This section provides a brief checklist of common failures. Before trouble- shooting or repairing the function generator, make s ure the failure is in the instrume nt rather than any external connection s. Also make sure that the instrumen t is accurately calibrated. The function generator’s circuits allow troubleshooting an[...]

Power Supply Problems WARNING SHOCK HAZA RD. Only service-trained personnel who a re aware of the hazards involved should remove the instrument covers. The procedures in this sec tion require that you connect the power cord to the inst rument with the covers removed. To avoid electrical shock and personal injury, be careful not t o touch the power-[...]

Self-Test Procedures Power -On Self-Tes t Each time the fu nction generato r is powered o n, a small set of self-tests are perf ormed. Th ese tests check t hat the min imum set of logic and measu rement har dware are function ing proper ly. The power- on self- test performs checks 601, 625, and 626. Complete Self-Test Hold the s hift key while turn[...]

605 Serial confi guration readback failed Th is test re-sends th e last 3 byte serial configur ation data to all the serial path (SERDAT, SERBCK, SERCLK). The data is then clocked back into U103 and c ompared against the original 3 bytes se nt. A failure occurs if the data do not match. This tests checks the serial data path through U301, U302, and[...]

112[...]

7 Replaceable Part s 7[...]

Replaceable Parts This chapter contains information to help you order replacement parts for your 33120A Function Generator. The parts lists are divided into the following groups:  33120-66521 Main PC Assembly (A1)  33120-66502 Front-Panel Display and Key board PC Assembly (A2)  33120A Mainframe  Manu factur er’s Lis t Parts are listed[...]

33120- 66521 – Main PC Assembly Reference Agilent Part Mfr. Mfr. Part Designator Number Qty Part Description Code Number C101-C102 0160-6497 78 CA P-FXD 0.1 uF 25 V 04222 12065C104KAT A C103-C105 0160-5945 26 CA P-FXD 0.01 uF 50 V 04222 08055C103KAT A C107 0160-5945 CAP-FXD 0. 01 uF 50 V 04222 08055C103KAT A C108 0160-6497 CAP-FXD 0. 1 uF 25 V 04[...]

Reference Agilent Part Mfr. Mfr. Part Designator Number Qty Part Description Co de Number C535-C536 0160-5952 2 CAP-FXD 330 pF 50 V 04222 08055A331JAT A C539-C540 0160-7721 2 CAP-FXD 82 pF +-1% 50 V CER C0G 04222 08055A820F ATMA C541-C542 0160-5965 2 CAP-FXD 150pF + -5% 50 V CER C0G 04222 08051A151JAT A C543-C544 0160-5967 CAP-FX D 100 pF 5% 04222 [...]

Reference Agilent Part Mfr. Mfr. Part Designator Number Qty Part Description Co de Number C1017-1019 0160-5947 CAP-FXD 1000 pF 50 V 04222 08055C102KAT A C1020-1021 0160-5945 CAP-FXD 0. 01 uF 50 V 04222 08055C103KAT A C1051-C1052 0160-6497 CAP-FXD 0.1 uF 25 V 04222 12065C104KAT A C1053 0180-4086 CAP-FXD .01 F +-20% 25 VDC S4217 SME25VN10 3M22X45 LL [...]

Ref eren ce Ag ile nt Part Mfr. Mfr. P art Designator Number Qty Part Descr iption Code Number JM1001-1004 0699-1503 7 RESISTOR .05 +-100% TKF 28480 0699-1503 JM1051 0699-1503 RESISTOR .05 +-100% TKF 28480 0699-1503 K501-K502 0490-1664 8 RELAY 2C 5VDC-COIL 1A 110VDC 28480 0490-1664 K601-K602 0490-1664 RELAY 2C 5VDC-COI L 1A 110VDC 28480 0490-1664 K[...]

Ref eren ce Ag ile nt Part Mfr. Mfr. P art Designator Number Qty P art Description Cod e Number R301 0699-1403 1 RESISTOR 31.6K +-1% .125 W TKF TC=0+ -100 28480 0699-1403 R302 0699-3211 2 RE SI S T OR 39. 2K 1% 1206 .125 W 200V TC=100 28480 0699-3211 R303-R304 0699-1318 RESISTOR 1K +-1% .125 W T KF TC=0+-100 28480 0699-1318 R305 0699-1391 RESISTOR [...]

Ref eren ce Ag ile nt Part Mfr. Mfr. P art Designator Number Qty Part Descr iption Code Number R629 0699-2712 RESISTOR 255 +- 1% .125 W TKF TC=0+-100 28480 0699-2712 R630 0699-1415 RESISTOR 100 +- 1% .125 W TKF TC=0+-10 28480 0699-1415 R631 0699-1432 RESISTOR 511 +- 1% .125 W TKF TC=0+-100 28480 0699-1432 R632-R633 0699-1384 RES ISTO R 4.6 4K +-1 %[...]

Reference Agilent Part Mfr. Mfr. Part Designator Number Qty Part Description Code Number R724 0699-1437 4 RESISTOR 825 +-1% .125 W TKF TC=0+-100 28480 0699-1437 R725 0699-1415 RESISTO R 100 +-1% . 125 W TKF TC=0+ -100 28480 0699-1415 R726-R727 0699-2064 2 RESISTOR 6. 8 +-5% .125 W T KF TC=0+-500 2M627 MCR18J R728 0699-1415 RESISTO R 100 +-1% . 125 [...]

Ref eren ce Ag ile nt Part Mfr. Mfr. P art Designator Number Qty P art Description Cod e Number R908 0699-1318 RESISTOR 1K + -1% .125 W TK F TC=0+-100 28480 0699-1318 R909 0699-3408 1 RESISTOR 1K +-5% 1 W TKF TC=0+ -200 2M627 MCR1001KJ R910 0699-1391 RESISTOR 10K + -1% .125 W TK F TC=0+-100 28480 0699-1391 R1001 0699-1380 3 RESISTOR 3.16K +-1% .125[...]

Reference Agilent Part Mfr. Mfr. Part Designator Number Qty Part Description Co de Number U301-U302 1821-0964 2 IC DRVR 8X S 20SOL 45V 250MA 01295 T PIC6595DW U303 1826-2793 1 IC DA VOUT SER 16SOL 16BIT AD1851R 24355 AD1851R U304 1821-0434 3 IC ANLG-MUXR/DEMUXR CMOS/HC 8-CHAN 18324 74HC4051D U305 1820-5790 1 I C S H F -R G T R C M O S / 74 HC S Y N[...]

33120- 66502 – Display and Keyboard PC Assem bly Ref eren ce Ag ile nt Part Mfr. Mfr. P art Designator Number Qty Part Descr iption Code Number C1101 0160-5945 3 CAP-FXD 0.01 uF 50 V 04222 08055C103KAT A C1102-1103 0180-3751 10 CAP -FXD 1 uF 35 V TA S0545 NRS105M35R8 C1104 0160-6497 3 CAP-FXD 0.1 uF 25 V 04222 12065C104KAT A C1105 0160-5947 CAP-F[...]

33120A Ma inframe Ref eren ce Ag ile nt Part Mfr. Mfr. Pa rt Designator Number Qty Part Descr iption Code Number A1 33120-66521 1 MAIN PC ASSEMBLY 28480 33120-66521 A2 33120-66502 1 DISPLAY AND KEYBOARD PC ASSEMBLY 28480 33120-66502 B1 3160-0847 1 FAN-TBAX 12V 5.3-CFM NOM 11855 DFB0412L-SG CBL1-CBL2 33120-61601 2 CABLE BNC 28480 33120-61601 CBL4 RS[...]

Manufacturer’s L ist Mfr Co de Manufacture r’s Name Manufac turer’s Ad dress Zip Code 00779 Am p In c Har risbu rg, P A, U. S.A. 17111 01295 Tex as Instru ments In c Dall as, TX, U.S.A. 75265 02113 Coilcraft In c Cary, IL, U.S. A. 60013 04222 AVX Corp Great Nec k, NY, U.S.A. 11021 04713 Motorola Inc Roselle , IL, U.S.A. 6 0195 05971 LYN -TRON[...]

8 Schematics 8[...]

Schematics  33120A Block Diagram . . . . . . . . . . . . . . . . . 129  Mechanical Disasembly . . . . . . . . . . . . . . . . . 130  Floating Logic Schematic . . . . . . . . . . . . . . . . 131  Digital Waveform Data Synthesis Schematic . . . . . 132  System DAC Schematic . . . . . . . . . . . . . . . . . 133  Waveform DAC Schemat[...]

Block Diagram 129 Fold Her e Fold Her e Fold Her e Fold Her e Ô Binder Edge (RH Page) Foldout Cut Size = 9 x 19 inches Ô Binder Edge (RH Page) Foldout Cut Size = 9 x 19 inches[...]

Mechanical Disassembly 130 Pull Off Handle Pull Off Bumpers Loosen Captive Screws Remove Bottom Screw Slide Off Outer Case Pull To Remove Press Down To Unlatch Cable Pull Up To Disconnect Remove Sc rew Pry Outward From This Side Front Panel Will Pull Off Fold Her e Fold Her e Binder Edge (LH Page) Foldout Cut Size = 9 x 19 inches Fold Her e Fold He[...]

33120-66521 (sheet 1 of 10) Floating Lo gic Schem atic 131 Fold Her e Fold Her e Fold Her e Fold Her e Ô Binder Edge (RH Page) Foldout Cut Size = 9 x 19 inches Ô Binder Edge (RH Page) Foldout Cut Size = 9 x 19 inches[...]

33120- 66521 ( sheet 2 of 10) Digital Waveform Data Synthesis Schematic 132 Fold Her e Fold Her e Binder Edge (LH Page) Foldout Cut Size = 9 x 19 inches Fold Her e Fold Her e Binder Edge (LH Page) Foldout Cut Size = 9 x 19 inches[...]

33120-66521 (sheet 3 of 10) System D AC Schematic 133 Fold Her e Fold Her e Fold Her e Fold Her e Ô Binder Edge (RH Page) Foldout Cut Size = 9 x 19 inches Ô Binder Edge (RH Page) Foldout Cut Size = 9 x 19 inches[...]

33120- 66521 ( sheet 4 of 10) Waveform DAC Schematic 134 Fold Her e Fold Her e Binder Edge (LH Page) Foldout Cut Size = 9 x 19 inches Fold Her e Fold Her e Binder Edge (LH Page) Foldout Cut Size = 9 x 19 inches[...]

33120-66521 (sheet 5 of 10) Filters Schema tic 135 Fold Her e Fold Her e Fold Her e Fold Her e Ô Binder Edge (RH Page) Foldout Cut Size = 9 x 19 inches Ô Binder Edge (RH Page) Foldout Cut Size = 9 x 19 inches[...]

33120- 66521 ( sheet 6 of 10) Sync, Square Wave, and Attenuator Schematic 136 Fold Her e Fold Her e Binder Edge (LH Page) Foldout Cut Size = 9 x 19 inches Fold Her e Fold Her e Binder Edge (LH Page) Foldout Cut Size = 9 x 19 inches[...]

33120-66521 (sheet 7 of 10) Output Amplifier Schematic 137 Fold Her e Fold Her e Fold Her e Fold Her e Ô Binder Edge (RH Page) Foldout Cut Size = 9 x 19 inches Ô Binder Edge (RH Page) Foldout Cut Size = 9 x 19 inches[...]

33120- 66521 ( sheet 8 of 10) Output Attenuator Sche matic 138 Fold Her e Fold Her e Binder Edge (LH Page) Foldout Cut Size = 9 x 19 inches Fold Her e Fold Her e Binder Edge (LH Page) Foldout Cut Size = 9 x 19 inches[...]

33120-66521 (sheet 9 of 10) Earth Refe rence Logic Sch ematic 139 Fold Her e Fold Her e Fold Her e Fold Her e Ô Binder Edge (RH Page) Foldout Cut Size = 9 x 19 inches Ô Binder Edge (RH Page) Foldout Cut Size = 9 x 19 inches[...]

33120 -6652 1 (shee t 10 of 10) Power Su pplies Sche matic 140 Fold Her e Fold Her e Binder Edge (LH Page) Foldout Cut Size = 9 x 19 inches Fold Her e Fold Her e Binder Edge (LH Page) Foldout Cut Size = 9 x 19 inches[...]

33120-66502 (sheet 1 of 1) Displa y and Ke yboard Schem atic 141 Fold Her e Fold Her e Fold Her e Fold Her e Ô Binder Edge (RH Page) Foldout Cut Size = 9 x 19 inches Ô Binder Edge (RH Page) Foldout Cut Size = 9 x 19 inches[...]

33120-66521 Componen t Locator Diagram 142 TOP SIDE 33120-66521 REV A Fold Her e Fold Her e Binder Edge (LH Page) Foldout Cut Size = 9 x 19 inches Fold Her e Fold Her e Binder Edge (LH Page) Foldout Cut Size = 9 x 19 inches[...]

TOP SIDE 33120-66502 REV C 33120-66502 Component Locator Diagram 143[...]

 Co pyright Agilen t Technolog ies, Inc. 1994-2002 No part of this manual may be repro- duced in any form or by any means (including elec tronic storage and retrieval o r translat ion into a foreign language) without prior agreement and writte n consent from Agile nt Techn ologi es as gover ned b y the United St ates and international copy right[...]