Converting National Semiconductor Models

National Semiconductor's circuit simulator has a scaled diode model that is not the same as that used by Star-Hspice. To use National Semiconductor circuit models, do the following:

For a subcircuit that consists of the scaled diode model, the subcircuit name must be the same as the name of the model.

The .PARAM statement inside the subcircuit specifies the scaled diode model parameter values. Add a scaled diode model inside the subcircuit, then change the .MODEL mname mtype statement to a .PARAM statement.

Ensure that all the scaled diode elements are preceded by the character X.

Check that every parameter used in the .MODEL statement inside the subcircuit has a value in the .PARAM statement.

Using the Scaled Diode Subcircuit Definition

The scaled diode subcircuit definition converts the National Semiconductor scaled diode model to a form a model usable in Star-Hspice. The .PARAM parameter inside the .SUBCKT represents the .MODEL parameter in the National circuit simulator. Replace the .MODEL mname statement by a .PARAM statement. Change the model name to SDIODE.

Example

An example of scaled diode subcircuit definition is:

.SUBCKT SDIODE NP NN SF=1 SCJA=1 SCJP=0 SIS=1 SICS=1
+ SRS=1

D NP NN SDIODE

.PARAM IS=1.10E-18 N=1.03 EG=0.8 RS=20.7E3

+ CJA=0.19E-15 PHI=0.25 CJP=0.318E-15

+ EXA=0.5 EXP=0.325 CTC=6E-4

+ TRS=2.15M M=2

*

.MODEL SDIODE D

+ IS='IS*SIS*SF' CJA='CJA*SF*SCJA' CJP='CJP*SF*SCJP'

+ RS='RS*SRS/SF' EXA=EXA EXP=EXP

+ N=N CTA=CTC CTP=CTC

+ TRS=TRS TLEV=1 TLEVC=1 xti='m*n'

.ENDS SDIODE

Note that all the parameters used in the following model must have a value that comes from either a .PARAM statement or the .SUBCKT call. The diode statements are then replaced by the call to the subcircuit SDIODE:

XDS 14 1048 SDIODE SIS=67.32 SCJA=67.32 SRS=1.2285E-2