What does a AC Sweep Simulation do?

An AC Sweep Simulation calculates the small signal response of the circuit, linearised around the Bias Point, when sweeping one, or more, sources over a range of frequencies. It does not take into account any non-linear effects, like clipping.

The Sweep Parameters are Start and End Frequency and, for a Linear sweep, the number of Points, and, for a Logarithmic Sweep, the number of Points per Decade, or Octave.

The Sweep drives any AC part, VAC for Voltage, or IAC for Current, and any sources that have an “AC” parameter, like the VSIN source.

The default value for the AC source is 1V pk-pk, 0.707Vrms, which is 0dB and this is the recommended value for the sources.

The results of the simulation will be available in the Probe Window.

In addition to the “vector” result, it is possible to plot the Real, and Imaginary components, the Magnitude, and Phase, dB level and Group Delay.

The waveforms can be changed using the available functions, or by modifying the waveform expression, for example:

The expression IMG(V(out)) is equivalent to VI(out) (Imaginary component)

The expression R(V(out)) is equivalent to VR(out) (Real component)

The expression DB(V(out)) is equivalent to VDB(out) (dB level)

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