User Guide

Chapter 12 Monte Carlo and sensitivity/worst-case analyses
296
Using resistors with models
To explore the effects of manufacturing tolerances on the
behavior of this circuit, you set device (DEV) and (LOT)
tolerances on the model parameters for resistors R1, R2,
R3, and R4 in a later step (see page 12-297
). This means
you need to use resistor parts that have model
associations.
Because R parts do not have associated models (and
therefore no model parameters), change the resistor parts
to Rbreak parts that do have models.
To replace R1, R2, R3, and R4 with the RBREAK part
1 Click R1 to select it.
2 Hold down the C key and click R2, R3 and R4 to add
them to the selection set.
3 Press D to delete the selection set.
4 From the Place menu, choose Part.
5 Type
RBREAK in the Part text box. (If RBREAK is not
available, click the Add Library button and select
BREAKOUT.OLB to configure it for use in Capture.)
6 Click OK.
7 Manually place the RBREAK part in the circuit
diagram where R1, R2, R3 and R4 were located.
8 Double-click on each RBREAK part and change the
reference designators as desired.
W
h
en PSpice runs a Monte Car
l
o ana
l
ysis, it
uses tolerance values to determine how to
vary model parameters during the
simulation.
Pspug.book Page 296 Wednesday, November 11, 1998 1:14 PM