User Guide

Chapter 4 Creating and editing models
88
* FIRST ORDER RC STAGE
.SUBCKT LIN/STG IN OUT AGND
+ PARAMS: C1VAL=1 C2VAL=1 R1VAL=1 R2VAL=1
+ GAIN=10000
C1 IN N1 {C1VAL}
C2 N1 OUT {C2VAL}
R1 IN N1 {R1VAL}
R2 N1 OUT {R2VAL}
EAMP1 OUT AGND VALUE={V(AGND,N1)*GAIN}
.ENDS
How are models organized?
The key concepts behind model organization are as
follows:
• Model definitions are saved in files called model
libraries.
• Model libraries must be configured so that PSpice
searches them for definitions.
• Depending on the configuration, model libraries are
available either to a specific design or to all (global)
designs.
Model libraries
Device model and subcircuit definitions are organized
into model libraries. Model libraries are text files that
contain one or more model definitions. Typically, model
library names have a .LIB extension.
Most model libraries contain models of similar type. For
vendor-supplied models, libraries are also partitioned by
manufacturer. To find out more about the models
contained in a model library, read the comments in the file
header.
You can use the OrCAD Model Editor, or any
standard text editor, to view model
definitions in the libraries.
For example: MOTOR_RF.LIB contains
models for Motorola-made RF bipolar
transistors.
Pspug.book Page 88 Wednesday, November 11, 1998 1:14 PM