Any independent source can be assigned a time-dependent value for transient analysis. The general form of pulse waveform is:

PULSE ( <V1> <V2> [TD [TR [TF [PW [PER [PHASE]]]]]] )


You must specify a value for the parameters V1 and V2. the remaining parameters, if not specified, assume a default value.

Parameter Description Units Default
V1 Initial amplitude of the output with respect to the negative terminal (usually ground). V o A  
V2 Pulsed value. Maximum amplitude of the output swing. V o A  
TD Time delay. Delay before the source changes from Initial to Pulsed. s 0
TR Rise time. Time it takes to rise from Initial Voltage to Pulsed Voltage. s TSTEP
TF Fall time. Time it takes to fall from Pulsed Voltage back to Initial Voltage. s TSTEP
PW Pulse width. Time that the source remains at Pulsed Voltage. s TSTOP
PER Period. Time between the start of the first pulse to the start of the second pulse. s TSTOP
PHASE Phase. degree 0

TSTEP is the printing increment and TSTOP is the final time (see the .TRAN control line for explanation).


VIN 3 0 PULSE(-1 1 2NS 2NS 2NS 50NS 100NS)

See also

Independent voltage source
Independent current source