> -----Original Message-----
> From: Roman Black [SMTP:fastvid@EZY.NET.AU]
> Sent: Friday, October 18, 2002 5:37 PM
> To:   PICLIST@MITVMA.MIT.EDU
> Subject:      Re: [EE]: Paralleling MOSFETs
>
> Sean H. Breheny wrote:
> >
> > Hi Roman,
> >
> > Sorry to take so long to reply. I tried out your idea (using two TO-3
> > darlingtons and 0.15 ohm emitter resistors) and it works really well.
> The
> > nice high slope of the Ic vs. Vbe curve (for current sharing) combined
> with
> > the larger device package really helps. Much cooler (the FETs were so
> hot
> > that you couldn't even momentarily touch them, you can keep your hand on
> > the darlingtons).
>
>
> Thanks Sean! Many of those big TO-3 darlingtons
> are good for 250W dissipation each! Let's see that
> from a TO-220 super-FET. <grin>
>
You can hardly compare a TO3 with a TO220 package, but there are quite
easily available MOSFET's in TO3 packages that are rated for 300 Watt
dissipation(e.h. IXTM67N10).  However, you don't need the hassle of a TO3
style mounting when you can get a plastic TO247 packaged device rated for up
to 400 Watts, and of course the mini-bloc devices that dissipate around 700
watts.

Not knocking bi-polars, I prefer using them to MOSFET's mainly because I
grew up with them and understand their strengths and weaknesses better, but
technology moves on and there are some fantastic devices around now.

Regards

Mike

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