Orcad Pspice purchase

I was complaining about something LTspice related once and someone here off ered a free copy of his spice which he said was just as good if not better. It might be a bit more mainstream and suit your needs. I think it was Su perspice perhaps? I believe he was not going to continue development and s o was letting people use it for free.

I don't know what is wrong with LTspice exactly as all the spice variants s eems to be mutually incompatible to some extent. If the TI spice is compat ible, Superspice might be as compatible.

What exactly is not compatible with LTspice? My understanding is they acce pt many different format options.

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ffered a free copy of his spice which he said was just as good if not bette r. It might be a bit more mainstream and suit your needs. I think it was Su perspice perhaps? I believe he was not going to continue development and so was letting people use it for free.

Superspice was developed and sold by Kevin Aylward. I bought a copy from hi m for my own use, and another for use where I worked at the time - Haffmans BV in Venlo in the Netherlands. It worked fine. I stopped using it when LT Spice came along - once we could post LTSpice .asc files here they became a superior replacement for ASCII art.

seems to be mutually incompatible to some extent. If the TI spice is compa tible, Superspice might be as compatible.

If you want perfect compatibility with some commercial electronic design ap plication, the people who supplied the commercial application aren't going to admit that LTSpice is close enough.

ept many different format options.

But nobody is going to promise that it is going to stay compatible forever, unless you give them money to make sure that it happens.

You have to amortize it into your quotes/charges for this customer. Short-term licences can be applied to specific projects - make it plain that orcad support is only provided under those conditions.

RL

Encrypted models, for one thing.

Cheers

Phil Hobbs

It can be an indirect screening tool for what level you're at; if you don't have it they don't hire you because what they're looking for is the consultant who drops 3 grand on software and never miss it, not "getting more consultant gigs what do I do" and frets about the price-guy.

Yep. LTSpice has encrypted models also, and all the major vendors have verbiage in their software licensing agreement about what they claim you may and may not do with their encrypted models (some of it of dubious legal validity but who can afford the best lawyers I wonder)

If an extra $300 a month in tooling budget is a deal breaker, then you're better off looking for other work.

. . . or just don't let them see YOUR budget.

RL

Okay but did say the late Jim Thompson tell prospective clients "Oh no I'm sorry I don't have a copy of this industry-standard tool for circuit simulation and design it cost $3000." I expect not.

You could use your excellent credit to take out a small business loan with a very favorable rate, write it off your taxes as a business expense immediately and then pay off over time and if you make $1 more from it than $3000 + interest - write off savings, adjusted for inflation over the loan term, you can define that as a win I guess.

It's a bit of a gamble but it's $3000 not $30,000. Sometimes it cost money to make money, sucks...

LTspice can't read PSPICE encrypted models. TI is being annoying, shipping those.

BTW: Has anybody had any luck with the new TI PSPICE models? The TINA ones are mostly useless, e.g. the OPA140 model that won't converge unless the supplies are *exactly* symmetrical, and often not even then.

Cheers

Phil Hobbs

He did tell them that he used "original crispy-flavor PSPICE" though. He didn't like the newer versions on account of the crappy schematic editor.

May God hold him in memory eternal.

Cheers

Phil Hobbs

Hardly anybody gets the supply pins right. Some opamps, connected to just a capacitor and ground, generate watts of power at kilovolts from their dumb internal current sources. Would that they would do that in real life.

Sometimes I use the power pins, for boosting and such. Can't trust the models.

I haven't tested many models for PSRR. I doubt many people do that right.

You'd hope that the reason for the encryption is that they're real transistor-level models rather than crappy macromodels (but I repeat myself).

Cheers

Phil Hobbs

Dream on, young man! Transistor models are too slow and too much work.

ADI is playing catch-up converting a zillion parts to LT Spice, and not doing that very well.

Well, encrypting a macromodel is just too lame a concept for me to even consider. Foundry models are pretty good, but proprietary of course.

Still waiting for the ADA4817 and a bunch of others. Have you run across bad models for the AD stuff?

Cheers

Phil Hobbs

Am 21.01.21 um 19:47 schrieb Phil Hobbs:

ADA4898.

One of them seems to work.

As soon as I have 2 of them in one circuit nothing converges.

National/TI models in LTspice work better for me than AD.

Gerhard

JT could probably have refused to use a computer, and still made a living.

RL

Taking out a line of credit is a common method of amortizing at lower interest. Unfortunately software isn't considered as a capital cost, for depreciation, and can't be resold, so you have to write it off in the first year.

RL

Why would you not want to? Worst case you have a loss carry-forward. I guess non-incorporated might be different.

Best regards, Spehro Pefhany