On 15 Jan 2003 at 23:00, Peter L. Peres wrote:

> On Wed, 15 Jan 2003, Roman Black wrote:
>
> *>> They are not faster than an equivalent sized (in amps of junction
> size) *>> standard silicon rectifier, rather slower. *> *>Is this
> right? How can you use them in a PWM *>hbridge if they are slower than
> standard rectifiers? *>In that use the diode may be on for 3x the time
> that *>the FET is on, surely this requires a fast and low *>Vf diode?
>
> When this is the case the clever designers turn on the fet's gate
> during this time. It is not hard to do.
> *>> TO220s that run 150W for any length of time tend to fail in my
> experience. *> *>Many are specced at 65W up. 150W sounds very
> excessive *>for a TO-220 pack. :o)
>
> Most MOSFETs in TO220 for 50V and 50A or so are specced to 150W. This
> is the upper limit of anything that comes in a TO220 case afaik and it
> is not so good to try it. Unless you have very exotic cooling
> arrangements (circulating oil bath or expanding compressed air or
> freon 'heat pipes' come to mind here).

The IRFBA90N20D that I mentioned is in a new kind of package called a
Super-220, and this part is spec'd at 650W. Yes, 650W. The package
has about the same outline size as a TO-220, "package limitation
current" is 95A. Not something that I have seen before, but looks
very interesting.

--
Brent Brown, Electronic Design Solutions
16 English Street, Hamilton, New Zealand
Ph/fax: +64 7 849 0069
Mobile/txt: 025 334 069
eMail:  brent.brown@clear.net.nz

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