Re: Wanted: LM-709 (Spice model) National Op-Amp

Mike Engelhardt wrote:
> Paul,
>
>> And, if you buy PSPICE for 10k and still spend the 5
>> or 10 million those two departments, the modeling and
>> process departments, you can still get good results for
>> transistor-level simulation. Linear Tech uses PSPICE
>> for IC design. I have been told that LT-Cad is just
>> a variant of PSPICE so I am somewhat baffled how people
>> can claim it works "better".
>
> You don't know what you're talking about. First of all,
> Linear has just about every SPICE simulator available.
> The opamp people at Linear do tend to use PSPICE(the
> Microsim/OrCAD/Cadence trademark) but that's because
> opamps are simple IC's that don't need the best simulation
> tools and have been done in PSPICE for very many years.
>
> By LT-Cad, I assume you mean LTspice. The only way
> that could be thought of a PSPICE variant would be
> because we hired one of the founders of Microsim
> at the start of the development of that project to
> find out things like how much time and money it took
> to develop. LTspice is otherwise a independently
> developed version of SPICE and is the world's highest
> performance SPICE with regard to speed, accuracy, and
> robustness.

What I will say here is that a work college, and myself on and off,
have been using LTSpice on some circuits very recently, like currently.
Sure, it converges most of the time when XSpice and Tanner spice, and
any others don't, however it still has problems on some circuits we have
been trying. This is to be compared with TISpice (internal Texas
Instruments spice). In a past life of 3+ years, it *never* failed to
converge, ever. It seemed to have 100 hundreds of algorithms to try
automatically. So, as far as robustness goes, I cant agree. Its good,
but not the best, imo. As for speed, I have never compared it to
TISpice.

Kevin Aylward
informationEXTRACT@xxxxxxxxxxxxx
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.


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