>
>At this frequency, you need a much faster (higher current) gate drive than
>what a PIC pin can provide.  The FET should be in transition only a small
>portion of the time, let's say under 1uS.  For sake of example, let's say
>the total gate charge is 50nC.  50nC / 500nS = 100mA.  That's a lot more
>than you can expect from a PIC pin, let alone one with a resistor in
>series with it.

I just hit this same issue with an AVR that's driving a mosfet at 250kHz as a constant current source. Same problem, ended up using a driver chip for $0.50 or so to solve the problem.  The driver's a fet also, but much smaller gate capacitance, so I can yank it up and down quickly.  If you can't switch them fast, they do get hot.

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