4.11  SFFM: Frequency Modulation time dependent value

4.11.1  Syntax

SFFM args
SFFM offset amplitude carrier modindex signal

4.11.2  Purpose

The component value is a sinusoid, frequency modulated by another sinusoid.


For voltage and current sources, this is the same as the Spice SFFM function, with some extensions.

The shape of the waveform is described by the following equations:
mod = (_modindex * sin(2*PI*_signal*time));
ev = _offset + _amplitude 
        * sin(2*PI*_carrier*time + mod);
For other components, it gives a time dependent value.

As an extension beyond Spice, you may specify the parameters as name=value pairs in any order.

4.11.4  Parameters

Offset = x
Output offset. (Default = 0.)

Amplitude = x
Amplitude. (Default = 1.)

Carrier = x
Carrier frequency, Hz. (required)

Modindex = x
Modulation index. (required)

Signal = x
Signal frequency. (required)