Re: [ng-spice] Readline Response


To ng-spice@ieee.ing.uniroma1.it
From Michele Quarantelli <quarante@legs.ing.unibs.it>
Date Mon, 30 Aug 1999 12:24:48 +0200
Delivered-To mailing list ng-spice@ieee.ing.uniroma1.it
In-Reply-To Your message of "Wed, 25 Aug 1999 22:41:12 +0200." <199908252041.WAA03965@legs.ing.unibs.it >
Mailing-List contact ng-spice-help@ieee.ing.uniroma1.it; run by ezmlm
Reply-To ng-spice@ieee.ing.uniroma1.it

> > 
> > 
> > On Wed, 25 Aug 1999, Michele Quarantelli wrote:
> > 
> > 
> > > A final note: I'm currently comparing the last release of Berkeley 
>Spice 
> > > (spice3f5fix) against ng-spice. During op simulation of a LNA amplifier 
> > > (including a grounded MOS device as a capacitor) I saw ng-spice 
>converging 
> > to 
> > > the wrong solution (i.e. vds not equal to zero) !!! I was using MOSIS 
>BSIM3
> > v1 
> > > model so I re-compiled the bsim3v1 code (with some modification ... of 
>cour
> > se)
> > > and ... same result !!! At this point I'm quite concerned with ng-spice 
> > > reliability ... Anyone having the same problem ?
> > ng-spice reliability is still to be tested. We changed the code in various
> > parts, and probably exploited an hidden  bug (or inserted a new one). Can
> > you send to the list the netlist and modelcards so that we can perform our
> > simulations and try to discover the bug ?
> > 
> Unfortunately I cannot release the netlist so far, but I'll try with some
> other circuit to see if I fall into the same pit.
> 
> > Anyway: did you compiled in the bsim3v1 code included in spice3f5fix or
> > another one ? I had the same problem linkng all three B3SOI models in a
> > single executable: the PD model did not converged for one test circuit,
> > while the spice compiled with the PD model only converged. May be I have
> > not understood something in device code.
> > 
> I used the bsim3 code from spice3f5fix plus I added the test for 
>compatibility
> with Cider implementation.
> 
> > 
> 
> Michele

I've tried ng-spice version 0.3 with the LNA: now OP analysis succedeed to
converge to the right (at least expected) solution even by using the BSIM3v3.2
code (just a warning on the wrong version ...) .
I compiled the package without the predictor enabled however I have doubts 
that
predictor can influence the OP analysis.

I will try compilation with the predictor enabled and I'll see ...

Regarding the test becnh there is an old benchmark suite at 
http://www.cbl.ncsu.edu/Benchmark_dirs/CircuitSim90.

This includes BJT, MOS2, MOS3, test set, some of them very large.


Michele




Michele



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