On Sun, 19 May 2002, Pic Dude wrote:

>Yep, my LED's require 20mA at 100% duty-cycle, but I'm
>operating them at 25% (4 digits).  I know I can go more
>but don't have the datasheet -- I feel certain that I
>won't damage them with 25ma at 25% duty-cycle.
>
>The fun part is that I just tried it (jumpered across
>the resistors to bypass them), and the intensity change
>was very difficult to notice, but it seemed to work well.
>(Not like I'll actually visualize the excess current on
>the port :-) But oh well, I'll behave and keep the R's.

Incidentally this can break your program if it relies on reading back the
outputted values anywhere in it, as overloaded ports do not read the
proper set level. Besides exceeding the SOA of the chip and inducing
enough on-die ground and Vdd voltage drops to make other internal
operations more prone to noise and glitches.

Peter

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