.STEP — Parameter Sweeps

This command causes an analysis to be repeatedly performed while stepping the temperature, a model parameter, a global parameter, or an independent source. The first .step dimension is sorted to be in increasing order so as not to confuse the waveform viewer.

General syntax:

.step [<oct, dec, lin>] <item> <start> <end> <incr>

Step sweeps may be nested up to three levels deep. This is not a limitation of the simulator, but merely a current restriction of the waveform viewer.

The value of <item> is swept between <start> and <end>. The number of steps is defined with the keyword oct, dec, or lin and <incr> according to the following table:

Keyword	Nsteps
oct	No. of steps per octave
dec	No. of steps per decade
lin	Step size

.step <item> list <value1>[ <value2> [<value3> ...]]

The value of <item> is assigned the listed values.

.step <item> file=<filename>

The list of values to be assigned to <item> is read from the file <filename>. This file can contain comments like a regular netlist. The numbers must be separated by whitespace or commas as described here.

The following are examples for <item>.

Voltage source v1:

Parameter RLOAD:

param RLOAD

NPN model parameter VAF of model 2N2222:

NPN 2N2222(VAF)

Temperature:

temp

Complete examples:

.step oct v1 1 20 5

Step independent voltage source V1 from 1 to 20 logarithmically with 5 points per octave.

.step I1 10u 100u 10u

Step independent current source I1 from 10u to 100u in step increments of 10u.

.step param RLOAD LIST 5 10 15

Perform the simulation three times with global parameter Rload being 5, 10 and 15.

.step NPN 2N2222(VAF) 50 100 25

Step NPN model parameter VAF from 50 to 100 in steps of 25.

.step temp -55 125 10

Step the temperature from -55°C to 125°C in 10°C steps.