Re: An extremely good MOSFET driver

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

Original poster: "K. C. Herrick by way of Terry Fritz <twftesla-at-qwest-dot-net>" <kchdlh-at-juno-dot-com>

Sue (& all)-

Thru-hole ICs--DIPs--for sure:  My old eyes are too poor to dream of
fussing with SMTs!

I checked the UC3865Q's data sheet: it appears to be for low-voltage use
only--& it includes a VCO which I would not have use for.  No charge pump
since it is not intended to drive a high-side MOSFET that is at any V.
higher than 22 or so.  Those IR 2110-type devices' charge pumps are
evidently quite high-impedance circuits.  Big electric fields mess them
up--at least, that's what I think I learned the hard way.

Ken

On Fri, 09 Aug 2002 23:20:35 -0600 "Tesla list" <tesla-at-pupman-dot-com>
writes:
> Original poster: "S Gaeta by way of Terry Fritz <twftesla-at-qwest-dot-net>" 
> <sgtporky-at-prodigy-dot-net>
> 
> Hi Ken,
> 
> This IC was used at my job on a switching supply to drive IRFP 460 
> mosfets.I
> have never tried to use the chip in a SSTC, so I don't know how it 
> would
> behave in a "TC environment". It might be worth experimenting with 
> though,
> since the IC does the work of cranking out the waveforms. The 
> supplies used
> to glitch up when subjected to a certain frequency (I forgot which 
> one)
> during the RF immunity test, so what you found with your chip may 
> also apply
> to this one. Also, that particular chip was SMT which is probably 
> denoted by
> the "Q" at the end. I think most of us (myself included) would want 
> to work
> with the through hole version.
> 
> Sue
> 
> ----- Original Message -----
> From: "Tesla list" <tesla-at-pupman-dot-com>
> To: <tesla-at-pupman-dot-com>
> Sent: Friday, August 09, 2002 5:08 PM
> Subject: Re: An extremely good MOSFET driver
> 
> 
> > Original poster: "K. C. Herrick by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <kchdlh-at-juno-dot-com>
> >
> > Sue (& all)-
> >
> > I might look that up--except that I had bad experiences with the 
> IR
> > 2110-type devices that incorporate a charge-pump for driving the 
> "top"
> > circuit.  The electric field from my secondary (apparently) 
> disrupted
> > that circuit; I thought it would be a nifty replacement for a 
> transformer
> > but I had to go back to transformer-coupling instead.
> >
> > Ken Herrick
> >
> > On Fri, 09 Aug 2002 11:55:01 -0600 "Tesla list" 
> <tesla-at-pupman-dot-com>
> > writes:
> > > Original poster: "S Gaeta by way of Terry Fritz 
> <twftesla-at-qwest-dot-net>"
> > > <sgtporky-at-prodigy-dot-net>
> > >
> > > > That's a NO NO!!!  A friend of mine who does power supply 
> design
> > > for a
> > > > living says you can get driver IC's which provide the 
> necessary
> > > time
> > > > delay between pulses, but I haven't gotten a typical part 
> number
> > > as yet;
> > > > will check with him and post that here if someone else hasn't 
> done
> > > so
> > > > already.  Same problem happens with push-pull self-excited
> > > transistor
> > > > inverters, of course, and makes the transistors get HHOOTT!
> > > >
> > > > Ed
> > >
> > >
> > > UC3865Q may be a very useful IC for this purpose.
> > > Sue
> > >
> > >
> > >
> > >
> >
> >
> 
> 
> 
>