> On Tue, 29 Oct 2002, Herbert Graf wrote:
> >         Yes, for the above reason, the PIC outputs are NOT
> current limited by
> > design, and certainly don't limit themselgves to only 25mA. TTYL
>
> But when you say that, you make it sound like there could be infinite(and
> damaging) current flow.

        Not infinite, but it could be damaging. I personally err on the side of
caution and assume that if I exceed the posted current draw I'll kill the
part. A little cautious perhaps but it has served me well (expect for those
times where I ignored my own rules and a puff of smoke resulted... :) ).

> Let me point out that the PIC has internal resistance (which varies
> depending on power supply voltage and pin polarity, among other things)
> which does, in fact, lead to a predictable limit on output current.

        True, but would you count on that for a production design? Unless Microchip
officially says "the output current is limited to 25mA" I wouldn't. For
experimenting sure.

> If you connect a PIC output to ground and try to drive it high, excessive
> current will flow. However an LED connected to ground is not ground. The
> voltage drop of the LED and the PICs resistance will limit the current to
> under 25 mA.

        Until Microchip changes something and doesn't tell us... they can do that
since that is not part of the spec sheet. TTYL

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