User`s guide

1
-
4 Thin
g
s You Need to Know
AC sweep and noise
These AC analyses evaluate circuit performance in response to
a small-signal alternating current source. Ta b le 1 - 2
summarizes
what PSpice A/D calculates for each AC analysis type.
Note
To run a noise analysis, you must also run an AC
sweep analysis.
Table 1-2
AC Analysis Types
For this AC
analysis...
PSpice A/D computes this...
AC sweep Small-signal response of the circuit
(linearized around the bias point) when
sweeping one or more sources over a range
of frequencies. Outputs include voltages
and currents with magnitude and phase; you
can use this information to obtain Bode
plots.
Noise For each frequency specified in the AC
analysis:
• Propagated noise contributions at an
output net from every noise generator in
the circuit.
• RMS sum of the noise contributions at
the output.
• Equivalent input noise.