next up previous contents
Next: FIT: Fit a curve Up: Behavioral modeling Previous: COMPLEX: Complex value   Contents

Subsections

EXP: Exponential time dependent value

Syntax

EXP args
EXP iv pv td1 tau1 td2 tau2 period

Purpose

The component value is an exponential function of time.

Comments

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

The shape of the waveform is described by the following algorithm:

ev = _iv;
for (reltime=time; reltime>=0; reltime-=_period){
  if (reltime > _td1){
    ev += (_pv - _iv) 
          * (1. - Exp(-(reltime-_td1)/_tau1));
  }
  if (reltime > _td2){
    ev += (_iv - _pv) 
          * (1. - Exp(-(reltime-_td2)/_tau2));
  }
}

Parameters

IV = x
Initial value. (required)

PV = x
Pulsed value. (required)

TD1 = x
Rise time delay. (Default = 0.)

TAU1 = x
Rise time constant. (Default = 0.)

TD2 = x
Fall time delay. (Default = 0.)

TAU2 = x
Fall time constant. (Default = 0.)

Period = x
Repeat period. (Default = infinity.)



Al Davis 2002-03-26