User Guide

Chapter 11 Parametric and temperature analysis
282
Overview of temperature analysis
For a temperature analysis, PSpice reruns standard
analyses set in the Simulation Settings dialog box at
different temperatures.
You can specify zero or more temperatures. If no
temperature is specified, the circuit is run at 27°C. If more
than one temperature is listed, the simulation runs once
for each temperature in the list.
Setting the temperature to a value other than the default
results in recalculating the values of
temperature-dependent devices. In EXAMPLE.OPJ (see
Figure 73), the temperature for all of the analyses is set to
35°C. The values for resistors RC1 and RC2 are
recomputed based upon the CRES model which has
parameters TC1 and TC2 reflecting linear and quadratic
temperature dependencies.
Likewise, the Q3 and Q4 device values are recomputed
using the Q2N2222 model which also has
temperature-dependent parameters. In the simulation
output file, these recomputed device values are reported
in the section labeled TEMPERATURE ADJUSTED
VALUES.
Figure 73 Example schematic EXAMPLE.OPJ.
Running mu
l
tip
l
e ana
l
yses
f
or
d
i
ff
erent
temperatures can also be achieved using
parametric analysis (see Parametric
analysis on page 11-272
). With
parametric analysis, the temperatures can
be specified either by list, or by range and
increments within the range.
T
h
e examp
l
e circuit EXAMPLE.OPJ is
provided with the OrCAD program
installation.
Pspug.book Page 282 Wednesday, November 11, 1998 1:14 PM