Converting National Semiconductor Models

National Semiconductor's SNAP circuit simulator has a scaled BJT model that is not the same as that used by Star-Hspice. To use this model with Star-Hspice, make the following changes.

For a subcircuit that consists of the scaled BJT model, the subcircuit name must be the same as the name of the model. Inside the subcircuit there is a .PARAM statement that specifies the scaled BJT model parameter values. Put a scaled BJT model inside the subcircuit, then change the ".MODEL mname mtype" statement to a .PARAM statement. Ensure that each parameter in the .MODEL statement within the subcircuit has a value in the .PARAM statement.

Defining Scaled BJT Subcircuits

The following subcircuit definition converts the National Semiconductor scaled BJT model to a form usable in Star-Hspice. The .PARAM parameter inside the .SUBCKT represents the .MODEL parameter in the National circuit simulator. Therefore, replace the ".MODEL mname" statement with a .PARAM statement. Change the model name to SBJT.

NOTE: All the parameters used in the following model must have a value that comes either from a .PARAM statement or the subcircuit call.

Example

.SUBCKT SBJT NC NB NE SF=1 SCBC=1 SCBE=1 SCCS=1 SIES=1 SICS=1

+ SRB=1 SRC=1 SRE=1 SIC=0 SVCE=0 SBET=1

Q NC NB NE SBJT IC=SIC VCE=SVCE

.PARAM IES=1			10E-18 		ICS=5.77E-18	NE=1.02 		NC=1.03

+ ME=3.61			MC=1.24		EG=1.12		NSUB=0

+ CJE=1E-15			CJC=1E-15 		CSUB=1E-15		EXE=0.501

+ EXC=0.222			ESUB=0.709		PE=1.16		PC=0.37

+ PSUB=0.698 			RE=75		RC=0.0		RB=1.0

+ TRE=2E-3 			TRC=6E-3 		TRB=1.9E-3		VA=25

+ FTF=2.8E9 			FTR=40E6 		BR=1.5		TCB=5.3E-3

+ TCB2=1.6E-6 			BF1=9.93 		BF2=45.7 		BF3=55.1

+ BF4=56.5 			BF5=53.5		BF6=33.8

+ IBF1=4.8P 			IBF2=1.57N 		IBF3=74N

+ IBF4=3.13U 			IBF5=64.2U 		IBF6=516U

.MODEL SBJT NPN

+ IBE='IES*SF*SIES' IBC='ICS*SF*SICS'

+ CJE='CJE*SF*SCBE' CJC='CJC*SF*SCBC'

+ CJS='CSUB*SF*SCCS' RB='RB*SRB/SF'

+ RC='RC*SRC/SF' RE='RE*SRE/SF'

+ TF='1/(6.28*FTF)' TR='1/(6.28*FTR)'

+ MJE=EXE MJC=EXC

+ MJS=ESUB VJE=PE

+ VJC=PC VJS=PSUB

+ NF=NE NR=NC

+ EG=EG BR=BR VAF=VA

+ TRE1=TRE TRC1=TRC TRB1=TRB

+ TBF1=TCB TBF2=TCB2

+ BF0=BF1 IB0=IBF1

+ BF1=BF2 IB1=IBF2

+ BF2=BF3 IB2=IBF3

+ BF3=BF4 IB3=IBF4

+ BF4=BF5 IB4=IBF5

+ BF5=BF6 IB5=IBF6

+ NSUB=0 sbet=sbet

+ TLEV=1 TLEVC=1

+ XTIR='MC*NC' XTI='ME*NE'

.ENDS SBJT

The BJT statement is replaced by:

XQ1 1046 1047 8 SBJT SIES=25.5 SICS=25.5 SRC=3.92157E-2

+ SRE=3.92157E-2 SBET=3.92157E-2 SRB=4.8823E+2 SCBE=94.5234

+ SCBC=41.3745 SCCS=75.1679 SIC=1M SVCE=1

Star-Hspice Manual - Release 2001.2 - June 2001