Hi all,

Most PICs are rated to being able to source up to 20mA and to sink up to
25mA at any pin. I understand that this is an Absolute Maximum Rating that
one cannot stress.

Now, keeping into the safe side, say that I want to source 15mA from ALL
output pins of a 16F84. Having up to 13 outputs, this would mean a total of
nearly 200mA out of the chip. The situation worsens if I choose to use a
16C73, for example, with 22 output pins ALL sourcing 15mA for a total of
330mA. For a 16C74, with 33 output pins, you go into the 1/2 Amp range...

Ok, so far so good, one cannot do that. So the question is: How do I compute
the maximum current a given chip can source at a time? I need to drive
several charges at (possibly) the same time and I am afraid of overloading
or overheating the PIC. I guess that if I find that it is too much for the
PIC I'd have to use transistors for driving my output charges.

Thank you in advance.

Regards,
Andres Tarzia
Technology Consultant, SMART S.A.
e-mail: atarzia@smart.com.ar