"Christopher Ott" spamtrap at ottelectronics dot com wrote in message
...
"tempus fugit" wrote in message
...
Hey all;

I want to drive LEDs directly from the outputs of a 74LS373N latch, but
I
can't figure out which parameter is the maximum current I can get from
it.
I've enclosed the data sheet. On p. 6, there's a then a different 1 on
p.
9
IOH High-level output current

and

IOL Low-level output current


then a different 1 on p. 9. Can anyone tell me which parameter I should
be
looking at? Or am I looking at teh wron g thing altogether?

Thanks

Looks like you can source 2.5ma, sink 24ma with a maximum of 40ma combined
total per device. The 74HC373 can do much better, sourcing or sinking 35ma
with a total of 70ma per device. I typically use a darlington driver array
to buffer LEDs from logic IC's. Lookup Digikey part number TD62083AF-ND.
It's cheap, TTL compatible, and can easily drive 8 high current LED's
without straining your logic IC.

Chris

Thankd guys.

So just to make sure I've got this straight - if I connect one lead of the
LED to the output of the latch and the other to ground, I've got 2.5mA, but
if I connect one lead to +5v and the other to the output of the latch, I've
got 24 mA? (Incidentally, I didn't even know you could connect the LED this
way...)

Thanks