I need a logic buffer for 8-bit microcontroller port, like 74HC244, but with an output current of more than 20mA, to drive high current LED. Any suggestion?
if your power is 3.3V, you can sonsider using TI's 74LVC244,
the speed is faster than 74HC244.
best regards
leotim said:
I need a logic buffer for 8-bit microcontroller port, like 74HC244, but with an output current of more than 20mA, to drive high current LED. Any suggestion?
I'm bumping this ancient thread because I think this is a good question and no one suggested one good option, which is to parallel multiple channels of an HC244 together. Most 244s claim a typical 6mA output drive (which I suspect is slightly conservative), so three 244 outputs tied together (with their inputs tied together as well, of course) should be able to source/sink 20mA. Just one more option to consider...
Sure, a Darlington would work too. It's just a good thing to know you can parallel identical FETs/CMOS logic and get higher current drive. A lot of times that's handy when you're only using a few of the channels in a device, but need more drive. You can use the unused channels to boost your drive.