LAB 3: DC Simulations and Circuit Modelingrmh072000/Site/Software_and_Links_files/3B_lab.pdf · Simulate and annotate the DC solution ... Lab 3: DC Simulations ... draw a symbol,
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a. Ifyouhavenotalreadycreatedthisproject,doitnow.Then,inthisnewproject,amp_1900,openanewschematicwindowandsaveitwiththename:bjt_pkg.Also,setanydesiredOptions>Preferences.
2. SetupagenericBJTsymbolandmodelcard.
a. Intheschematicwindow,selectthepalette:Devices–BJT.SelecttheBJT_NPNdeviceshownhereandinsertitontotheschematic.
b. InserttheBJT_Model(modelcard)shownhere.
c. DoubleclickontheBJT_Modelcard.Whenthedialogappears,clickComponentOptionsandinthenextdialog,clickClearAllforparametervisibility–thenclickApply.ThiswillremovetheGummel‐Poonparameterlistfromtheschematic.Keepthisdialogopen.
d. Next,inBJT_Modeldialog,selecttheBfparameterandtypeinthewordbetaasshownhere.Also,clickthesmallbox:DisplayparameteronschematicforBfonlyandthenclickApply.Betaisnowaparameterofthiscircuit–lateronyouwilltuneitlikeavariable.
e. SetVaf(ForwardEarlyVoltage)=50anddisplayit.
f. SetIse(E‐Bleakage)=0.02e12,anddisplayit.ThenclosethedialogdialogwithOK.Thedevicenowhassomemorerealisticparameters.parameters.
g. FortheBJT_NPNdevicesymbol,removetheunwanteddisplayparameters(Area,Region,TempandMode)byuncheckingthebox.Thisbox.Thiswillmaketheschematiclesscrowdedwithtext.
a. InsertlumpedLandCcomponents:Insertthreeleadinductorsof320pHeachandtwojunctioncapacitorsof120fFeach.Besuretousethecorrectunits(picoandfemto)oryourcircuitwillnothavethecorrectresponse.Tip:typeLorCincomponenthistorytogetthecomponentsontoyourcursorwithoutusingthepalette.
b. AddsomeresistanceR=0.01ohmstothebaseleadinductoranddisplaythedesiredcomponentvaluesasshown.
c. Insertportconnectors:Clicktheportconnectoricon(shownhere)here)andinserttheconnectorsexactlyinthisorder:1)collector,collector,2)base,3)emitter.YoumustdothissothattheconnectorsconnectorshavetheexactsamepinconfigurationastheADSBJTBJTsymbol.
d. Edittheportnamesasshowhere:changeP1toC,changeP2toB,andchangeP3toE.
e. Cleanuptheschematic:Positionthecomponentssothattheschematicisorganized–thisisgoodpractice.Tomovecomponenttext,presstheF5key,selectthecomponent,andpositionthetextusingthecursor.
a. Toseethedefaultsymbol,click:View>Create/EditSchematicSymbol.WhentheSymbolGeneratordialogappears,clickOKandthedefaultsymbolwillappear.
b. Next,aboxorrectanglewiththreethreeportsisgenerated:defaultsymbol.However,deletethissymbolsymbolusingthecommands:SelectSelect>SelectAll.Thenclickthethetrashcaniconordeletekey.key.
c. Returntotheschematic‐click:Viewclick:View>Create/EditSchematic.
b. IntheGeneraltab,maketheseschanges:1)changetheComponentInstanceNametoQ,2)changetheSymbolNametoSYM_BJT_NPNbyclickingthearrowandselectingit(thisisthebuilt‐insymbol),3)inthe
c. ClickSaveAELFiletowritethesechangesbutdonotclosethisdialogyetbecauseyoustillneedtosetotherparameters.
d. GototheParameterstab.IntheParameterNamearea,typeinbetaandassignadefaultvalueof100byclickingtheAddbutton.BesuretheboxtoDisplaytheparameterischeckedasshownhere.ClicktheOKbuttontosavethenewdefinitionsanddismissthedialog.
e. Intheschematicwindow,Savethedesign(clicktheiconshownhere)tomakesureallyourworkcreatingthissub‐circuitwillnotbelost.Inthenextsteps,youwillseehowtheDesignParameterswillbeused.
a. Inthecurrentschematicofthebjt_pkg,clickFile>NewDesign.Whenthedialogappears,typeinthename:dc_curvesandselecttheBJT_curve_tracertemplateasshown.ClickOKandanewschematicwillbecreatedwiththetemplate,readytoinsertbjt_pkg.
b. SavethedesignandthenclicktheComponentLibraryicon(shownhere).
c. Whenthedialogopens,selectProjects>Amp1900andthenclickanddragthebjt_pkgintotheschematicandinsertitasshownhere.Everycircuitthatyoubuildwillbeavailableintheprojectlibraryasasub‐circuit.
d. Connectthebjt_pkgcomponentasshown.Youmayhavetoadjustthewiresandtext(F5)tomakeitlookgood.Also,youcannowclosethelibrarywindowandsavethedc_curvesdesignagain‐itisgoodpracticetosavedesignsoften.
a. ChangetheParameterSweepIBBvaluesto:0uAto100uAin10uAstepsasshownhere.DonotchangetheDCsimulationcontrollerdefaultsettingsforsweepingVCE–theyareOK.NoticethattheVAR1variables(VCE=0andIBB=0)donotrequiremodificationbecausetheyareonlyrequiredtoinitialize(declare)thevariableforthesimulator.
8. Simulateatbeta=100and160.
a. Simulate(F7)withBeta=100.Afterthesimulationisfinished,thedatadisplaywillwillappearwiththecurvetracerresults(data(datadisplaytemplate).Trymovingthemarkermarkerandwatchtheupdatedvaluesappear.appear.
b. SimulateagainwithBeta=160bychangingchangingthevaluedirectlyontheschematic.Youshouldseetheupdatedvalues.
c. Verifythevaluesforbeta=160andVCE=3V,whereIBB=40uAandIC=3mAwithabout10mWofconsumedpowerIfnot,checkthedesign.
a. Savethecurrentschematic:dc_curves.Inthesamewindow,createanewdesign(withoutatemplate)named:dc_bias.ThensavethedesignbyclickingontheSaveCurrentDesignicon(shownhere)sothatitiswrittenintotheADSdatabase.
b. Also,savetheDataDisplay.
c. GototheADSMainwindowandverifythatyourprojecthasthreedesignsandthedatadisplayasshownintheProjectView.
d. Also,lookattheFileViewtoseetheDatadirectorywherethesimulationdatasetsarewritten.Clickonthe+toexpandthedirectoryfolderand–tocloseit.Andthenlookinthenetworksdirectoryfolder–thisiswheretheschematicdesigns(.dsn)arewritten.
e. ClickontheFileViewandthenthetheProjectViewtabs‐noticethatthethatthetoolbariconschange.
f. IntheFileViewtabmode,clickthetheiconsforStartupandWorkingdirectorytodirectorytoseehowtheywork.Youwork.Youcanalwaysbrowsethethefilesofanydirectoryandcomecomebacktoyourworkingdirectory,suchasamp_1900.amp_1900.
a. Insertthebjt_pkgusinglibraryiconorthecomponenthistory.Nowpushintothebjt_pkgandclickFile>DesignParameters.Resetthebetaparameterdefaultto160,popoutanddeletethebjt_pkgandreinsertit–betaisnow160wheneveryouusethemodeledcircuit.
b. FromtheProbecomponentspaletteorcomponenthistory,insertanI_ProbeandrenameitICinsteadofI_Probe1asshownhere.YoucanalsogetthecurrentfromthesimulationbysettingtheDCcontrollerOutputtabforPinCurrentsbuttheprobeiseasytouseinthiscase.
c. FromtheSourcesFrequencydomainpaletteorusingcomponenthistory,insertadcsupplyandcurrentsourceandsettheirvaluesasshown:Vdc=3VandIdc=IBBasshownhere.
d. Wirethecomponentstogetherandaddtheground(groundicon).
e. InsertaDCsimulationcontroller(DC).Edit(doubleclick)thecontrollerandgototheSweeptabandassign:IBB:10uAto100uAin10uAsteps(besuretouseuAunitsbecausethesweeptabisgeneric).ThengototheDisplaytabandcheckthesettingstobedisplayedasshown.ThenclickApplyandOK.
a. Inthedatadisplay,insertanequationandtype:Rb=(3–VBE)/IBB.
b. SelecttheRbEqnandusethekeyboardCtrlCandCtrlVtocopy/pasteit–itwillbecomeRb1.
c. HighlighttheRb1equationasshownandchangeittobecomeRc:Rc=2/IC.i.ThetotalDCsupplywillbe5volts.Therefore,with3voltsVCE,2voltsremainforthecollectorresistor.
d. InsertanewListandscrolldowntotheEquationsmenu(shownhere),andaddRbandRc.Theneditbothcolumnheadingsonthelistwithabracketed[3]asshown.Thisreferencesthe40uAIBBusingitsindexvalue[3].Indexvaluesbeginatzero:0,1,2,3,etc.YoucanalsousePlotOptionstoaddalabeltothelistasshown:
a. Savethedesign(dc_bias)withanewname:dc_net.Bythistime,youshouldknowhowtodothis(File>SaveDesignAs).Also,saveandclosethedc_biasdatadisplay.
b. Modifythedesignasshown.BeginbydeletingthecurrentsourceIBB,theI_Probe,andtheVarEqn.
c. GototheLumpedComponentspaletteorusecomponenthistory,R,toinsertresistorsforthebase(56kOhm)andcollector(590Ohm)resistorsasshown.Youmayneedtouserotatetoinsertitcorrectly.
e. SettheV_DCsupply:Vdc=5V.Wirethecircuitandorganizeit.
f. DeletetheDCsimulationcontrollerandputanewoneinitsplace–thisisfasterandmoreefficientthanremovingthesweepsettings.Becausethereisnosweep,youdonothavetosetanythingtocheckDCvalues.
a. UsetheSimulate>SimulationSetup(orHotKeyHotKey“S”ifyouhavesetit)andunchecktheboxtheboxtoopendatadisplayaftersimulation.simulation.
b. ClickSimulate>Simulate,oronaPCtrytheF7keyboardkey,torunthesimulation.Thedatasetnamewillbethesameastheschematic–thisisthedefault.Youcanverifythisbyreadingthestatuswindow:
c. Annotatethecurrentandvoltagebyclickingonthemenucommand:Simulate>AnnotateDCSolution.Ifnecessary,movecomponentsorcomponenttext(F5key)toclearlyseethevaluesofvoltageandcurrent.Besurethatyouhavethesamevaluesshownhere.Ifnot,checkyourwork,includingthesub‐circuit.
d. Cleartheannotation,click:Simulate>ClearDCAnnotationandthenSaveallyouwork.Closeallwindowsifnordoingtheoptionalstepsthatfollow.
14. OPTIONAL:SweepComponentModelTemperatures
a. EdittheDCcontroller–selectitandclicktheediticon.
b. IntheSweeptab,entertheADSglobalvariabletemp(defaultisCelsius)andenterthesweeprange:55to125withstepsize=5.Also,intheDisplaytab,clicktheboxestodisplaytheannotationonthecontroller–clickApplytoseeitandOKtodismissthedialog.
c. InsertVCandVBEnode/pinlabels.
d. Setthesimulationdatasetnametodc_temp,andandchecktheboxtoopenthedatadisplaydc_net.dc_net.ClickApplyandthenSimulate.
e. PlotVCandVBEinarectangularrectangularplot.Thesewillbevs.bevs.tempwhichisthesweptvariable.YoucouldalsousetheAddtheAddVsfunctionbutitisnotnotnecessarywhenthereisoneonesweptvariable.
f. Puttwomarkersoneachtraceindeltamodetoseethechangeinvoltageastemperaturechanges.Theplotshouldlookliketheoneshownhere:collectorvoltagedecreasesatalmostone‐halftherateofVBEasthetemperatureincreases.Youcanusethistemperaturesweepmethod(sweepingtheglobalvariable“temp’)foranyADSsimulation.