Tagged Questions

3
votes
3answers
60 views

Does this buffer's current rating apply to each individual output, or all of them?

I'm thinking of using a SN74ABT244A octal buffer in a circuit that requires the buffer to sink 20mA of current on all eight outputs under worst-case input conditions. In the datasheet, it says that ...
5
votes
1answer
888 views

Should I calculate a resistor value for driving indicator LEDs from TTL outputs?

Traditionally I have always used a \$1\:\mathrm{k\Omega}\$ resistor as a current limiting resistor for driving an LED direct from a TTL (or 5V CMOS) output. I can't remember how I came by this value ...