Re: [Help-gnucap] pspice to gnucap

[al davis]

On Mon, Jun 16, 2003 at 10:08:05AM +0800, Fernan Bolando wrote:
> I have tested the bjt set of models from the cadence/pspice on bjt.
> basically the results are similar

Thanks.  That is reassuring for both.

> .. except pspice doesn't accept some model
> file naming convention used by pspice. The model below is results in
> "invalid type" error. Gnucap doesn't allow a slash"/" and or dash"-" in the
> .model. 

I think the parser splits tokens on /.  I will look into changing it.
For now, you know how to work around it.

>    As for the Vacuum tube models I checked intusofts implementation and it
> seems they use the "B" type to model tubes, since the "B"type is already in
> the works is it practical to model vacuum tubes using modelgen?

Part of the code for the Spice-3 "B" device is there.  Part isn't.  I
do plan to add it.  General expressions are also needed for Verilog-A
support, which is also in the works.  So, the same work has multiple
applications.

Modelgen takes a different approach.  Models done with the "B" device
in Spice are inefficient.  It doesn't hurt much for small circuits and
simple models, but with complex models it would be prohibitive.
Modelgen allows you to completely specify a complex model.  Once you
do, it will be as efficient as the built-in models.  The built-in
models were made with modelgen.

I have seen some of the tube models, and they are fairly simple.  They
will be even simpler taking advantage of the features of modelgen.  I
believe it should be at most a few days work to translate such a
model.

In addition to the efficiency, you also get the advantage of being
able to specify it as a regular device, with parameters, .model
statements, probes, etc.

If you do, please send it to me so I can include it for all to use!