Getting into Spice

If you skip the Linux idea, "Switcher CAD III", a Spice simulator, available for free at the Linear Technology website is a good starting point, There are a few example circuits using the LT SMPS chips. But you can equally well use the software for simulating your discrete circuits. Give it a try, it is really fun using it.

Regards

Thomas

Thomas Gallenkamp said

There's also a great Yahoo group too. (Wish is was an NNTP newsgroup tho')

Not necessary. From the guy who maintains LTspice:

No need to "skip the linux idea"; Switchercad runs fine under wine (in linux).

If this contains analog elements in conjunction with logic models don't get your hopes up too much. Sometimes it works, sometimes it's less time consuming to built a real prototype instead before spending hours to try to figure out why it won't converge.

Regards, Joerg

Any Spice is only as good as the models. I do quite well using the built-in 'HC' models in PSpice.

The trick is the logic models must also include an analog interface when they are used in mixed-signal situations.

Convergence issues are almost always cockpit error ;-)

...Jim Thompson

Hello Jim,

Which is why I went from Spice to Weller. Before I go looking for better models I have it whipped up in the lab. Which reminds me, after the Weller I've got to fire up the Weber.

Yes, I know. But I tried wiggling all levers and breakers and we are still losing altitude :-(

Regards, Joerg

Hello Jim,

It was the models. Using the 74HC14 from Helmut Sennewald did it, now the oscillator runneth with normal reltol settings. They are on the Yahoo LTSpice group file section.

IIRC they still don't but it converges.

Regards, Joerg

I would imagine that a 74HC14 model by Helmut would be device level, NOT behavioral.

PSpice logic models are behavioral so that, in logic-analysis-only mode, they are screamingly fast. However, they are cleverly designed such that attaching an analog device to them activates an analog interface... which I suspect is your problem.

...Jim Thompson

Hello Jim,

That is a neat trick. In my case I almost never use them as pure logic and if I do there is not need to simulate. I'll need the full circuit including substrate diodes. Because often I am, ahem, using these in some unorthodox fashion.

Regards, Joerg

It's possible that I have device-level models for what you need.

Contact me privately and I'll see what I can provide to you.

...Jim Thompson

Hello Jim,

Thanks, did that via the email link on your site. We just came back from Black Angus. Had a roasted French dip sandwich, along with a Guinness.

Regards, Joerg

"Joerg" a écrit dans le message de news:4tR1g.18075$ snipped-for-privacy@newssvr27.news.prodigy.net...

Huh. What's that?

Bonjour Fred,

Thinly sliced roast on a baguette (which they call french roll), with herbs, spices and a sauce to dip it into. The sauce is almost the best part. Then there are french fries. I know, I know, according to Asterix they were invented in Belgium when the Romans wanted to invade ;-)

Regards, Joerg

available

try,

Nonsense, it is known to be very happy running in wine. It is perhaps the best behaved program for testing wine. (It may work even if nothing else does.)

available

try,

That's not all, there is Geda and friends (GAF) a true GNU / Linux implementation of a full electronic EDA suite.