User`s guide

AC Sweep Analysis 10
-3
• Digital devices hold the states that PSpice A/D calculated
when solving for the bias point.
• Because AC sweep analysis is a linear analysis, it only
considers the gain and phase response of the circuit; it does
not limit voltages or currents.
The best way to use AC sweep analysis is to set the source
magnitude to one. This way, the measured output equals the
gain, relative to the input source, at that output.
Settin
g
Up an AC Stimulus
To run an AC sweep analysis, you need to place and connect one
or more independent sources and then set the AC magnitude and
phase for each source.
To set up an AC stimulus
1
Place and connect one of these symbols in your schematic:
For volta
g
e input
Use
this...
When you are runnin
g
...
VAC An AC sweep analysis only.
VSRC Multiple analysis types including AC sweep.
For current input
Use
this...
When you are runnin
g
...
IAC An AC sweep analysis only.
ISRC Multiple analysis types including AC sweep.
Note
Unlike DC sweep, the
AC sweep analysis setup
dialo
g
box does not include
an input source option.
Instead, each independent
source in your circuit contains
its own AC specification for
ma
g
nitude and phase.
If you are plannin
g
to run a DC or
transient analysis in addition to
an AC analysis, see
If you want
to specify multiple stimulus
types on page 3-25 for additional
information and source symbols
that you can use.