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Blasting a Design with Power Mosfet Models

There's a wide variety of power mosfets all with complicated dynamics.

Has anyone created a large modern mosfet spice library for LTspice with models from many sources... Then set up LTspice to try each mosfet model one after another with results all together on one graph. (If capable..) That way the optimum mosfet can be found for a given application..

The mosfet library file can made smaller by only having mosfets with V,I, and P specs that suit the app.

Something like that is going to have a long run time but the computer can run while I'm sleeping.. :)

Comments...? D from BC

Reply to
D from BC
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If you use Spice power MOSFET models to select a suitable MOSFET for a design you are likely to be disappointed. That's because there's scarcely a perfect power MOSFET Spice model out there, and the few really good ones work well primarily only for certain aspects they were optimized to be good at. Most, if not all, are downright awful when compared against certain types of bench measurements. You'll be much better off studying datasheets and performing the relevant circuit calculations with the MOSFET data.

Reply to
Winfield Hill

I'm just discovering that.. I got the Infineon library and tried the SPA21N50 model (it's a subckt) in LTspice. All I get is singular matrix errors in my app. If I use a VDMOS mosfet model (LTSpice), it's ok.

It should be possible someday to do a "run all mosfets" routine in spice.. I was just curious if there was a lazy way to compare power dissipation between power mosfets operating above 100khz.

Well... back to the traditional method...Math, datasheets and bench testing. Until the models and software get better :)

D from BC

Reply to
D from BC

You left out using the manufacturer's tables of their MOSFET properties to pick out candidate parts. These should have reasonably-low, but not too low Ron, and not too high Ciss, etc. Select a preferred package and see if it's available in stock anyplace. Etc.

Reply to
Winfield Hill

Shopping for mosfets is like shopping for music...Not too hard and not too soft.. :)

I do use the web tables to narrow down the search but there can be still many candidates per manufacture..

Who's on top now in producing mosfets approaching the ideal high speed power switch? (+100W application). Maybe I can just focus on one manufacture...say Fairchild?? D from BC

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D from BC

Looking for mosfets reminds me of the story of Goldilocks and the Three Bears.. :)

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"Every member of the bear family has their own unique chair, porridge, and bed, which have unique characteristics. " D from BC

Reply to
D from BC

"D from BC" schrieb im Newsbeitrag news: snipped-for-privacy@4ax.com... | | Shopping for mosfets is like shopping for music...Not too hard and not | too soft.. :) | | I do use the web tables to narrow down the search but there can be | still many candidates per manufacture.. | | Who's on top now in producing mosfets approaching the ideal high speed | power switch? (+100W application). Maybe I can just focus on one | manufacture...say Fairchild??

As far as I can tell Fairchild is one of the topmost candidates (if cost is included). I recognized that every manufacturer specialized in specific subfields here.

Would be a nice feature for LTspice to run libraries as batch for comparision.

- Henry

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Reply to
Henry Kiefer

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