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

Mike:
Well if you will have a garbage-posting dishonest creep
like me to your four-hour seminar I feel the least I can
do is attend.  I'll talk to Gary Sapia in the local
sales office about the seminar.  Thanks for the invite.
Look for the guy in the back row wearing a Nixon mask.

There are actually other people in the world competent
to evaluate well-written source code.  I suspect several
read this group.  And it is a well-accepted fact that
open-source projects always result in improved results.
I am not an open-source nut however.  I will defend to the
death your right to maintain and sell proprietary code.

A half million lines of code. A half million lines of code.
Wow.  And accepted software productivity is between 5 and
10 lines of debugged implemented code per day.  200 work days
in a year.  So half a million line is what... 250 man-years
of code. Wow.  I knew Swanson overworked his people and there
are all kinds of LT burnouts and walking-wounded here in the
valley but I had no idea how bad it was over there.  My
software consultant buddies say that right around 600 or 700k
lines of code any program becomes un-maintainable so you still
have some room to grow if needed.

Lighten up Panama.  And don't worry so much about protecting
your software and all the arcanities inside it.  No one here
really cares about the indirect pointers to the linked lists
and malloc call recursive gobbledy gook. We just care if
it will give decent results on real-world circuits.  Thanks
to two posters here in the group, (analog and Helmut),I think
we will soon know.

Mr. (Dr./Prof?) Thompson:
What do you use?  I hope it is not some proprietary thing
like Analog Devices' internal SPICE. I hope you will serve as
judge jury and executioner in our little test.  And remember
everyone-- in my opinion we are mis-applying SPICE.  The
acronym stands for "Simulation Program with Integrated
Circuit Emphasis"  It is not SPBLE.  Spible would be
"Simulation Program with Board-Level Emphasis".  This is
why there seems to be such passions aroused when us board
guys say we don't worship SPICE the way IC designers do.
BTW, Dave Tamura in the CAD department at National rolled his
eyes when I told him I said Process and Modeling departments
cost 5 or 10 million dollars a year for a big semiconductor
company.  He hinted that tens times those numbers is not
unheard of.  He also said that his CAD department is also
involved in making sure the models conform to reality.

Helmut:
I will take it upon myself to find the EDN article.  Worse
comes to worse I will call Williams, he should remember it.
Then everybody can use it as a benchmark.  I will also release
one of my schematics to the public domain to see how all these
packages do with it.  I have to believe you guys when you say
LTspice is really good and fast.  Like my brother says: "An
ounce of trial is worth a pound of opinion."

I just hope EDN didn't use an LM709 (;^o)-

And everybody:  Watch the Tina-TI presentation on CMP's
EE Times webseminar to see how that SPICE did not predict
the real circuit results until they added caps to model board
strays.  Of course they used a milled board and that is a
whole 'nuther thread.
It is archived and was shot on Sept 14th
http://cmpnetseminars.com/TSG/?K=On24&Q=265

And on a completely different subject:
Who wrote the Masstech layout program that Orcad bought and
incorporated into Orcad?

Paul


Mike Engelhardt wrote: 
Paul,


I do agree if there is no sanctioning body like IEEE or
W3C or anybody to validate the claim for an improved
engine, one has to be more critical.  How can one judge
the advance of proprietary standards unless you guys
start opening up your code so the community can see the
difference in the source?  Sorry if you feel I am posting
garbage, I am trying to be positive.



Well, I'm not trying to be negative you do post garbage.
You can't evaluate a simulator's performance by looking at
the source code and you should know better.  I don't know
if you're deliberately dishonest or ignorant.  LTspice is
close to a half million lines of code.  You have to compile
it and test the program to see its performance.  I'm guessing
your comment is more dishonest than ignorant because it
appears to be an empty challenge to release the source code
of LTspice and trying to couple that challenge with a
challenge of proof of LTspice's performance, presumably
hoping one topic will drop with the other.

But it's not very hard to understand why LTspice runs faster
and is more accurate then other/earlier SPICE engines.  I
occasionally give 4hr seminars that explain in some detail
what one needs to do to make a better SPICE engine.  People
are surprised that I reveal all, but the trick is I tell what
one needs to do, not how to go about writing that code.  There
is an arraingment with an officer of LTC that prevents loss
of any of the planet's intellectual property in the event of
my death so that how to implement this code is not lost when
I die.  Anyway, in the seminar, I demonstrate the
fantastically improved accuracy of the core LTspice solvers
and the corresponding improvements in simulation speed with
live simulation runs.  Anyway those with legitimate interest
in LTspice can contact your local LTC office and request
when/where the next seminars will be(please don't contact me,
I have people smarter than me that schedule them).  The
seminars are worldwide.

--Mike 


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