I downloaded a BSIM3 model which contains a lot of parameters. Its definition is like this:
.MODEL CMOSN NMOS ...
Now I want to define a model based on this BSIM3 model which just adds W, L parameters.
I add this directive and modify the symbol model name.
.model MOSW CMOSN L=0.25u W=0.375u
When I run, I get the error message:
m2:Can't find definition of model "mosw"
The error log tells me:
Unknown model type "cmosn" -- ignored
It seems that this way not works. So how to define a SPICE model based an existed model?
Best Answer
The manual for NGSpice gives the minimal model for a MOSFET as follows:
The word
NMOS
is a device keyword, indicating the name of a kind of device that Spice knows about. (It is not the name of a "base" model. Level defines the mathematical model. See manual section 11.2)You can give parameters in the instance or in another model.
So you take your
and make