User Guide

Monte Carlo analysis
297
Saving the design
Before editing the models for the Rbreak resistors, save
the schematic.
To save the design
1 From Capture’s File menu, choose Save.
Defining tolerances for the resistor models
This section shows how to assign device (DEV) and lot
(LOT) tolerances to the model parameters for resistors R1,
R2, R3, and R4 using the model editor.
To assign 2% device and 10% lot tolerances to the resistance
multiplier for R1
1 Select R1.
2 From the Edit menu, choose PSpice Model.
Capture searches the libraries for the Rbreak model
definition and makes a copy to create an instance
model.
3 To change the instance model name from Rbreak to
Rmonte1, do the following:
a In the Model Text frame, double-click
Rbreak.
b Type
RMonte1.
4 To add a 2% device tolerance and a 10% lot tolerance
to the resistance multiplier, do the following:
a Add the following to the .MODEL statement (after
R=1):
DEV=2% LOT=10%
The model editing window should look something
like Figure 79.
5 From the File menu, choose Save.
By default, Capture saves the RMonte1 .MODEL
definition to the design_name.lib library, which is
You can use t
h
e mo
d
e
l
e
d
itor to c
h
ange t
h
e
.MODEL or .SUBCKT syntax for a model
definition. To find out more about the
model editor, see Editing model text
on page 4-110, or refer to the online
PSpice Reference Manual .
To
f
in
d
out more a
b
out a
dd
ing mo
d
e
l
libraries to the configuration, see
Configuring model libraries
on
page 4 120
Pspug.book Page 297 Wednesday, November 11, 1998 1:14 PM