Re: igbt drive question

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jan Wagner by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jwagner-at-cc.hut.fi>


> Are igbt driven the same as mofet? I have read that
> they drive the same and want to replace the mofets in
> my half bridge  but they are costly and I don't want
> to blow them. I no longer blow fets :), should the
> igbt be safe?

I'm trying to do the same thing, replace mosfets with igbts. It seems
that igbts do require a bit higher peak gate currents and do have
higher switching losses as well, and don't handle overcurrent as well
as mosfets would. The drive circuitry can essentially be the same as
for fets.

Ok but I don't know much about igbts yet - and actually have a
question too: igbts seem to have an built-in emitter=>collector diode
as well. How fast are they (reverse recovery)? Should the diode be
disabled for SSTC operation? This would lead to a pretty expensive
series shottky with 30A or higher...?

I know that multiresonant welder psu's don't use extra diodes around
the igbts, so probably in SSTC they are also unnecessary? Or???

 - Jan
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