parameter description default value units v1 initial value volts or amps v2 pulsed value volts or amps td delay time 0.0 seconds tr rise time tstep seconds tf fall time tstep seconds pw pulse width tstep seconds per period tstop seconds
If any of the parameters td1, td2, ... appear, the period is ignored, and the pulse is repeated for the delays td1, etc. The output will be a superposition of these pulses. A single pulse is described by the following table:
time value 0 v1 td v1 td+tr v2 td+tr+pw v2 td+tr+pw+tf v1 tstop v1
Intermediate points are determined by linear interpolation. It is not an error to omit unused parameters, for example the specification
vxx 3 0 pulse(0 1 2n 2n)describes a voltage which, starting from 0, begins rising at 2 nanoseconds, reaching 1 volt at 4 nanoseconds, and remains at that value.
This function applies only to transient analysis, where time is the running variable. When referring to default values, tstep is the printing increment and tstop is the final time in transient analysis, see 2.7.9 for explanation.