On 1/29/07, Wouter van Ooijen <wouter@voti.nl> wrote:
> >  And what's hapening if Q3 drain-source or Q3 internal diode is short
> > circuiting....
> > :)
> > Are you always believe into the OTG USB power supply as
> > current limiting ?
> > (like it should...)
>
> if either shorts *and* USB is not current limited you have a two-fail
> situation, one component failure and one design failure. If you want to
> be robuust against that you should also consider more weird (but
> single!) failures, like USB power is >48V, and/or has its polarity
> reversed. You can't design against all combinations of failures...

No you can't. But at least you should try.
USB power greater than 48V could be found only in software...
:)

Vasile
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