Simulation software for DC/DC converter

PSpice has a ton of library parts which is a major advantage. But I found two disadvantages:

a. For me it was not very stable, it crashed a lot. The old Microsim DOS version never did that, it was IMHO of much better quality.

b. If you simulate a whole big DC/DC converter on the device level and without any behavioral code in there it can take a very long time for each run to finish. This is why I prefer Linear Technology parts where feasible. They simulate a lot faster.

What parts do you need?

Do you really need to simulate an entire dc/dc converter?

Where did this schematic come from?

What's the purpose of the simulation?

If you'don't know this, then I'm not sure that any simulator can prove satisfactory.

RL

I don't find too much of that to be useful... crappy modeling from manufacturers :-(

You probably were, by then, using OrCAD? That's the most crashing software ever invented.

Yep, Best schematic capture ever.

But the core PSpice simulator is the same.

And fits LTC models best. ...Jim Thompson

It sure is. But you were always blaming me and my PC for that :-)

Acrobat Reader is a close 2nd though. A problem that largely went away for me after switching to a non-Adobe reader (Foxit). I sure don't miss those hard freezes.

Problem is, the guys in Outsourcia must have lost the wherewithall how to hook it up correctly.

It steers a lot of business towards LTC. I think Mike Engelhardt has earned his keep many times over. He and whoever made the business decision to invest in the LTSpice effort should get fat bonus checks.

I kept suggesting going back to MicroSim Schematics.

(A friend at ON_Semi passed along to me the fixes in the INI file so you can port to PCB software. The OrCAD people were (and are) too dumb to actually neuter the software, so the just killed (grayed-out) buttons via the INI ;-)

I don't use "Reader", I use the full Acrobat v7 Pro, for the "making PDF" features, then down-convert to v4 :-)

Yep. But PSpice can do a lot of mixed mode stuff that LTspice can't (and was never meant to) do...

... and find vague instabilities ;-) ...Jim Thompson

You don't get the simulator with that, plus last time I tried they had some serious limitations in there. Maybe to deter people to "sponge off" and then live with older software.

CAD is not the issue, I simply defected from Orcad and found software of a much better quality.

As long as that's legit, fine, but I won't use hacked software.

My impression of Adobe SW is not at all a positive one so I prefer other solutions. This is why companies should make sure their free versions are perfect. Because those act as a business card for the paid stuff.

So far I can't complain. I have used fairly weird math stuff in there. Lately I had some run-ins with convergence or where it felt like I was trying to pull a 5-ton trailer with a micro-car. But after some massaging LTSpice plodded through. Walked the dogs while it was crunching, and the computer warmed up the office nicely (it's almost winter again here).

Sure you do, you just need to know how to insist.

...Jim Thompson

So how does this work? You have to fall onto your knees?

No, Just say you won't pay for any more "updates". ...Jim Thompson

Too late. I have already done that many, many moons ago. Never looked back.

You can buy a lot of processors and RAM for the price of a copy of PSPICE, and LTspice is multithreaded at least to some degree.

Cheers

Phil Hobbs

Yes, and last time I used PSpice I was not so enthused. Plus by now I have built up a decent repository of LTSpice sim files so there is no point in switching unless I really have to. Same with my CAD, I might just keep that until the fork falls out of my hand. If only for the fact that I dread to re-create all those custom library parts.

Both programs are something like 98% perfect so if any other SW wants to have a chance it had to be 99.9%. And PSpice ain't, IMHO.

You might try TINA. There is a free version from TI, and it has some of=20 their models. I have the low end paid version but I rarely use it. = LTSpice=20 suits my needs, and I usually use it just for parts of my designs. For = the=20 whole thing, I get out the toolbox and soldering iron and scope.

Paul

Any luck getting TINA op amp models to run in LTspice? Most other simulator models can be fixed up just by rearranging the pin assignments in the model, but I've had problems doing that with TINA models.

Cheers

Phil Hobbs

Unless they're encrypted, there shouldn't be an issue. Send me one, original, versus your modification, and I'll see if I can decipher the problem. ...Jim Thompson

ice

the

To get a TI model to run on LTspice, I had to ramp up the supply voltages rather slowly. In another case I had to actually change the circuit to what I wanted AFTER it was up and running!

Once I had a problem with TINA itself that even the knowledgeable FE couldn't resolve, and never heard back from his question to corporate people. The sftware is like TI had made a simulation tool for the 'idiot' engineer [PSpice for Dummies], which is ok when first starting, but later need some control over what's going on, and not have it so 'automatic', making 'assumed' decisions..

Have you tried National's online simulator?

For that matter, I've had occasional minor problems getting LT models running in 3F5/P/XSpice environments. LT1213 seems to generate a lot of singular matrix errors, anyone else seen this?

Tim

TI didn't write TINA (the TI is not Texas Instruments ;-). It's from an Eastern European company (Design Soft). Even the Pro version is a toy. It's really intended to be a teaching aid, rather than a serious simulator.