RE: [ng-spice] OP-AMP linux
XSpice actually added backward compatibility for polynomial controlled
sources, but I'm not sure if it ever worked correctly when the polynomial
sources were within subcircuits. At least when I ported their code into my
spice 3f5 engine, it didn't work correctly within subcircuits, but it was
close... I think that I had a problem with the ordering within the naming
convention, i.e. there is an internal spice naming convention with the
subcircuit's name, then the part name's first letter, then something else...
probably for the referred variables within the polynomial controlled source.
Anyway, if I seem confused on the details, it's probably because I am.
If you want to "automatically" convert the subcircuits, you can do so with
B2 spice a/d 2000... using the device editor, you can load the subcircuit as
a new part, then look at the converted subcircuit text. However, it's not a
linux program, so that defeats the purpose.
Also, I think that Tuinenga's pspice book has the formula for converting the
terms into a polynomial.
I don't have the formula offhand... but it might be in the b2 spice a/d user
manual/ help file.
Here's a little blurb from the b2 spice a/d 2000 help file.
E1 1 2 poly(3) (3,0) 1 0 0 3
the corresponding spice3 (and B2 Spice) implementation is:
BE1 1 2 V= 1 + 3 * V(3)^3
B2 Spice has the capability to convert from spice2 polynomial controlled
syntax to spice3 arbitrary source syntax when they are embedded in
subcircuit models.
Using the Database Editor, create the simulation model from the text file
containing the subcircuit model. Depending on how you do this, the Database
Editor may automatically convert the polynomials for you. If not, choose
the button named Fix Controlled sources and the database editor will perform
the conversion.
E.g. (the first line is commented out- it's the old polynomial controlled
source.)
* egnd 99 0 poly(2) (3,0) (4,0) 0 .5 .5
begnd 99 0 v =0 + .5 * v(3,0) + .5 * v(4,0)
Good luck,
-Jon
-----Original Message-----
From: Gillespie, Alan [mailto:Alan.Gillespie@analog.com]
Sent: Wednesday, October 24, 2001 12:02 PM
To: 'ng-spice@ieee.ing.uniroma1.it'
Subject: RE: [ng-spice] OP-AMP linux
I think polynomial sources were dropped in spice3. They
were replaced with the arbitrary source (B) device. If
you can get hold of manuals for both spice2 and spice3,
you should be able to convert the two lines with poly()
in them to B devices. I'm afraid I can't remember the
old syntax, off-hand,
Cheers,
Alan
> -----Original Message-----
> From: rapela [mailto:rapela@usc.edu]
> Sent: 24 October 2001 16:58
> To: ng-spice@ieee.ing.uniroma1.it
> Subject: [ng-spice] OP-AMP linux
>
>
> Hello,
>
> First, I am a linux fun. Second, I am taking a course in
> linear circuits
> and I need to use an opamp in spice. I have installed spice3f4 and
> realized that there was not a card for an opamp. I asked my
> TA about how
> to use opamp with my linux version of spice and he told me
> that I should
> go to Win because spice under linux does not have opapms. It would be
> something really sad to go to windows so I am trying to get an opamp
> model.
>
> I found a macromodel for the ua741 (attached file ua741.inc) and when
> I tried to use it (comparator.cir) I got the following errors:
>
> ********************
> Error on line 30 : e:test:gnd test:99 0 test:poly(2)
> test:(3,0) (4,0) 0 .5
> .5
> unknown parameter (test:)
> Error on line 31 : f:test:b test:7 test:99 p:test:oly(5) vb
> vc ve vlp vln
> 0 10.61e6 -10e6 10e6 10e6 -10e6
> unknown parameter (vb)
> Fatal error: f:test:b: unknown controlling source p:test:oly
> doAnalyses: No such parameter on this device
>
> run simulation(s) aborted
> ********************
>
> I am new to spice and if something could point me to a model
> for any opamp
> or tell me what am I doing wrong with ua741.ing. I will
> really appreciate
> it.
>
> Thanks in advance, Joaquin
>
> ----------------------------------
> Joaquin Rapela
> PhD Student, Signal and Image Processing Institute
> University of Southern California
> 3740 McClintock Ave, EEB 424
> Los Angeles, CA 90089-2564
> tel: (213) 740-6430
> fax: (213) 740-4651
> ----------------------------------
>
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