.STEP

.STEP [LIN] TEMP start stop step
.STEP DEC|OCT TEMP start stop steps_per_interval
.STEP [LIN] PARAM param_name start stop step
.STEP DEC|OCT PARAM param_name start stop steps_per_interval
.STEP [LIN] model_type model_name(model_parameter) start stop step
.STEP DEC|OCT model_type model_name(model_parameter) start stop steps_per_interval
.STEP [LIN] source start stop step
.STEP DEC|OCT source start stop steps_per_interval
start Start value
stop Stop value
step Increment value
steps_per_interval Number of steps per decade (DEC) or octave (OCT)
param_name Parameter name (as usually defined using .PARAM)
model_type One of: CAP, D, NJF, PJF, NMOS, PMOS, NPN, PNP, LPNP, RES, VSWITCH, ISWITCH, NIGBT
model_name Model name (name after .MODEL in model statement)
model_parameter Model parameter name
source Reference for voltage or current source

The .STEP statement provides compatibility with other simulators and is not expected to be used for other purposes. Multi-step analyses would usually be defined using the SWEEP keyword on the same line as the analysis statement. See Multi Step Analyses for further details.

.STEP defines a single level multi-step analysis and must be accompanied by an analysis statement (.dc, .ac, .tf, .noise or .tran).

In this topic:

Single Step Sweeps - Interaction with .PROBE

.STEP can be used to define AC, NOISE and TF sweeps that sweep a variable other than frequency. It is neither necessary nor recommended to use .STEP to do this with SIMetrix, but it is the only way to achieve this in some other simulators.

For example, the following runs an AC analysis while sweeping he current source I1 at fixed 100kHz frequency: 

.AC LIN 1 100k 100k
.STEP DEC I1 1u 100m 25

The AC analysis specifies just a single point at 100kHz while the .STEP statement varies I1 from 1u to 100m. In SIMetrix this will do exactly the same analysis as the following: 

.AC DEVICE=I1 DEC 25 1u 100m F=100000

However, the .AC/.STEP analysis statements shown above will behave differently if a .PROBE statement is present in the netlist. .PROBE enables the creation of a PSpice format .DAT data file. The .DAT format does not support swept variables other than frequency but does support multiple single point analyses. So if .PROBE is present the above .STEP/.AC combination will perform multiple single point AC analyses which will create compatible data in the .DAT file.

Examples

Step voltage source VDC from 0 to 5 in 0.1 steps 
.STEP VDC 0 5 0.1
Step parameter R1 from 1k to 10k in steps of 500 
.STEP PARAM R1 1k 10k 500
Step temperature from 0 to 100C in 5C steps 
.STEP TEMP 0 100 5
Step current source I1 from 1uA to 100mA logarithmically with 50 steps per decade 
.STEP DEC I1 1u 100m 50

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