| Sinusoidal waveform |
Any independent source can be assigned a time-dependent value for transient analysis. The general form of sinusoidal waveform is:
| SIN ( <VO> <VA> [FREQ [TD [THETA [PHASE]]]] ) |
You must specify a value for the parameters VO and VA. the remaining parameters, if not specified, assume a default value.
| Parameter | Description | Units | Default |
| VO | DC offset voltage or current. Used to adjust the DC bias of the signal generator with respect to the negative terminal (usually ground). | V o A | |
| VA | Peak amplitude of the sinusoid. | V o A | |
| FREQ | Frequency of the sinusoidal voltage or current. | Hz | 1/TSTOP |
| TD | Delay time until the source voltage commences. Provides a phase shift of the output by delaying the start of the sine wave. | s | 0 |
| THETA | Damping factor. Sets the rate at which the sinusoid decreases in amplitude. A positive value results in an exponentially decreasing amplitude; a negative value results in an exponentially increasing amplitude. | 1/s | 0 |
| PHASE | Phase shift of the sinusoid at time zero. | degree | 0 |
TSTOP is the final time (see the .TRAN control line for explanation).
The sinusoidal waveform produces an exponentially damped sine wave.
The waveform value generated by the sinusoidal option is as follows:
| Time | Value |
| 0 to TD | VO+VA*sin(2∏*PHASE/360) |
| TD to TSTOP | VO+VA*e-(t-TD)*THETA*sin(2∏*(FREQ*(t-TD)+PHASE/360)) |
VIN 3 0 SIN(0 1 100MEG 1NS 1E10)