I'm sure there are lots of app-notes out there. I guess if someone
went through the trouble of a FAQ, it ought to be in very simple,
non-technical terms. It should definitely explain what the specs in the data
sheet mean. How to turn it on, how to turn it on/off fast (eg what's the
effect of gate capacitance and why that means you really do want lots of
current into the gate). Seems the things that most frequently confuses
people is 1) driving a high-side N-channel FET: gate-source voltage means
voltage from gate to source. if the source isn't sitting at ground, then
you'd better increase the voltage applied to the gate by that amount! and 2)
how to properly select a FET for your application. People most often look at
the max current and voltage ratings, perhaps the Rds(on) and select a device
based on that. Hmm. Maybe the FAQ needs a primer on power ratings and power
dissipation (especially during switching)? And maybe a few simple diagrams
to illustrate the concept? Or perhaps i'm making it out to be more
complicated than it really is?


> -----Original Message-----
> From: Roman Black [mailto:fastvid@EZY.NET.AU]
> Sent: Friday, July 20, 2001 11:33 AM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: Re: [EE]: IRL540 MOSFET Question
>
>
> Eisermann, Phil [Ridg/CO] wrote:
> >
> > Remember that gate voltage of the upper FET has to be +Vt
> (+5) above the
> > source voltage.
>
> > I didn't follow this thread. Are you using heatsinks? PWM?
> Do you only have
> > 5V available?
>
>
> Seems that even in the few months i've been on
> the piclist there seems to be an awful lack of
> info on how to make a good h-bridge, and/or
> how to use many of the good h-bridge chips that
> are available. Most of the experienced guys can
> do it but there is a never ending stream of
> newbies with h-bridge questions.
>
> Maybe someone should put up a h-bridge page??
> Piclist h-bridge FAQs?? Suggestions?
> -Roman
>
> --
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>
>

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