User Guide

Chapter 10 Transient analysis
264
During a transient analysis, any or all of the independent
sources may have time-varying values. In EXAMPLE.OPJ,
the only source which has a time-varying value is V1
(VSIN part) with attributes:
VOFF = 0v
VAMPL = 0.1v
FREQ = 5Meg
V1’s value varies as a 5 MHz sine wave with an offset
voltage of 0 volts and a peak amplitude of 0.1 volts. In
general, more than one source has time-varying values.
Figure 64 Example schematic EXAMPLE.OPJ.
The transient analysis does its own calculation of a bias
point to start with, using the same technique as described
for DC sweep. This is necessary because the initial values
of the sources can be different from their DC values. To
report the small-signal parameters for the transient bias
point, use the Transient command and enable Detailed
Bias Point. Otherwise, if you simply want the result of the
transient run itself, you should only enable the Transient
command.
In the simulation output file EXAMPLE.OUT, the
bias-point report for the transient bias point is labeled
INITIAL TRANSIENT SOLUTION.
T
h
e examp
l
e circuit EXAMPLE.OPJ is
provided with the OrCAD program
installation.
Pspug.book Page 264 Wednesday, November 11, 1998 1:14 PM