SImulating electricalcircuitsusingNetlist description

Seminar

Prof : Rogelio PalomeraProf:RogelioPalomera

TA:AndresSalazarLlinas

What is a NetlistWhatisaNetlist

Connectivity description of an electronicConnectivitydescriptionofanelectronicdesign.

The heart of any Cadence (Spice) file which is TheheartofanyCadence(Spice)file,whichissimplya list ofcomponentsandthe nets (ornodes) that connect them togethernodes)thatconnectthemtogether.

Circuit Simulation ProcessCircuitSimulationProcess

CreateSchematic

GeneratetheNetlist File GeneratetheNetlist File

Setupsimulationparameters

R Si l ti

RunSimulation

RunSimulation

Example 1Example1

*Example 1

VS10AC1SIN(0VOFF1VPEAK2KHZ)

R1121K

C1 2 0 0 032UFC1200.032UF

*ANALYSIS

.ACDEC51010MEG

S 00 S.TRAN5US500US

*VIEWRESULTS

.PRINTACVM(2)VP(2)

.PLOTACVM(2)VP(2)

.PLOTTRANV(1)V(2)

PROBE.PROBE

.END

CommandsCommands Devices:Nameacomponent,designatethenodeswhereit'sconnected,andgiveitavalue.RS 1 2 1000 VOLTAGE SOURCE VOLTAGESOURCESINEWAVE,PULSE,AC,DCSIN({voffset}{vpeak}{freq}{tdelay}{damp_factor}{phase})PULSE({v1}{v2}{tdelay}{trise}{tfall}{width}{period}) AC AND TRANSIENT ANALYSISACANDTRANSIENTANALYSISPerformbothAC(frequency)AnalysisandTransient(time)Analysis.Alsoperformanumberofotheranalyses

likeDC,Sensitivity,NoiseandDistortion..AC[LIN][OCT][DEC]{points}{start}{end}.DC[LIN]{varname}{start}{end}{incr}.DC[OCT][DEC]{varname}{start}{end}{points}.FOUR{freq}{outputvar}Examples:.FOUR10KHzv(5)v(6,7).IC{{vnode}={value}}*Initial ConditionsExamples:.ICV(2)=3.4V(102)=0.TRAN{print step value}{finaltime}[{noprint time}Examples:.TRAN5NS100NS PLOTTINGRESULTSPLOT [DC][AC][NOISE][TRAN] [ [{ i bl }*].PLOT[DC][AC][NOISE][TRAN][[{outputvariable}*]Examples:.PLOTDCV(3)V(2,3)V(R1)I(VIN).PROBE[outputvariable]*

Commands IICommandsII CONTROLLEDSOURCESVoltage Controlled Voltage Source VCVS.E{name}{+node}{node}{+cntrl}{cntrl}{gain}Examples:EBUFF1210111.0 Current Controlled Current Source CCCS Current Controlled Current Source CCCS.F{name}{+node}{node}{vsource name}{gain}Examples:FSENSE12VSENSE10.0 Voltage Controlled Current Source VCCS Voltage Controlled Current Source VCCS.G{name}{+node}{node}{+control}{control}{gain}Examples:GBUFF1210111.0 Current Controlled Voltage Source CCVS.Current Controlled Voltage Source CCVS.H{name}{+node}{node}{vsource name}{gain}Examples:HSENSE12VSENSE10.0

HowtoobtainaVoltageCurrenthCharacteristiccurve

*CurrentsourcefortestingI1 0 1 d 1AI101dc1A

R1121kd123mod1

Vsupply2 3 0 1Vsupply2301

.modelmod1d

*Analysis.dcI10.0010.0010.00005

.probeV(2)

.end

Netlist Simulation using CadenceNetlist SimulationusingCadence

GotoAllProgramsCadenceSPBCAMSSimulator AMSSimulator

Open a New Text FileOpenaNewTextFile

IntroducetheNetlist Descriptionofh d f ltheCirctuit andsaveitas.cirfile

Go to FileOpen and open the .cir fileGotoFileOpen andopenthe.cirfile

Go to Run ButtonGotoRunButton

Check if the simulation is completedCheckifthesimulationiscompleted

Go to the Add Trace ButtonGototheAddTraceButton

Choose your OutputsChooseyourOutputs

IfyouwanttoseetheOutputfile.Gol f ltoSimulationOutputfileButton

Getallthedataaboutyoursimulationlresults

Creating a SubcircuitCreatingaSubcircuit

A subcircuit is similar to a subroutine in softwareAsubcircuit issimilartoasubroutineinsoftwareprogramming.

This saves the tedium of creating multiple blocksThissavesthetediumofcreatingmultipleblocksofacircuitusedinmanyplaces.

The subcircuit is defined by the statements: Thesubcircuit isdefinedbythestatements:.SUBCKT ...

S b i it d fi itiSubcircuit definition.

.ENDS

Example 2Example2

We want to create a model for an OpAmpWewanttocreateamodelforanOpAmp *SINGLEPOLEOPERATIONALAMPLIFIERMACROMODEL*connections: noninverting input * | inverting input * | | output * | | || | | .SUBCKTOPAMP1 1 2 6 *INPUTIMPEDANCE RIN 1 2 10MEG *DCGAIN(100K)ANDPOLE1(100HZ) EP13012100K RP1341K CP1401.5915UF *OUTPUTBUFFERANDRESISTANCE EOUT 5 0 4 0 1 ROUT 5 6 10 EOUT50401ROUT5610 .ENDS

NowIntroduceyoursubcircuit toyourdesignExample2

VS 1 0 AC 1 SIN(0 1 10KHZ)VS 1 0 AC 1 SIN(0110KHZ)R1 1 25KR2 2 310KXOP1 023 xOPAMP1R3 4 010KR4 4 510KXOP2 3 4 5 xOPAMP1XOP2 345 xOPAMP1**SINGLEPOLEOPERATIONALAMPLIFIERMACROMODEL*connections:noninverting input*|inverting input*||output* | | |*|||.SUBCKTxOPAMP1126*INPUTIMPEDANCERIN1210MEG*DCGAIN(100K)ANDPOLE1(100HZ)EP1 3012100KRP1 341KCP1 401.5915UF*OUTPUTBUFFERANDRESISTANCEEOUT 50401ROUT5610.ENDS**ANALYSIS.TRAN 0.01MS0.2MS.PLOTTRANV(1)V(5).PROBEV(1)V(5).END

Homework1) Page330.Book:MicroeLectronic circuits4th Edition.Sedra/Smith.Example4.18Fig4.76.

Getthesimulationresultsusingnetlist.ACanalysisandTRANanalysisforRe=100ohmsandRe=10ohms.

2)Page462.Book:MicroeLectronic circuits4th Edition.

Sedra/Smith.Example5.13.Fig5.76.

G t i l ti lt f th CMOS i tGetsimulationresultsfortheCMOSinverter.

ExerciseExercise GettherealmodelsfortherequiredcomponentsandobtainthesimulationresultsfortheOutputcurrentandOutput

Voltage. Use a resistor of 8Kohms to simulate the speaker. Input Voltage V1 . 10 mVpp at 10 KHzVoltage.Usearesistorof8Kohmstosimulatethespeaker.InputVoltageV1.10mVpp at10KHz

ReferencesReferences SPICE:AGuideto Circuit Simulation andAnalysis Using PSpice,PaulTuinenga,3rdEdition,PrenticeHall,1995,ISBN013

1587757.158775 7.

The Spice Book,Andrei Vladimirescu,JohnWiley &Sons,Inc.,1994,ISBN0471609269.

PSpice andCircuit Analysis,JohnKeown,Third Edition,Merrill(Macmillan PublishingCompany),1997,ISBN0132354586.