question about fan-out experiment

Thread Starter

mr.harm

Joined Nov 24, 2008
29
Hello,
It is a question in my pre-lab manual. The experiment is about measuring the current (output) and voltage (output) of a 7404 when deriving another 7404's. Mesuring first when deriving only one 7404 and then two.. till reaching 10 7404's. The question why is it better to apply 5V(high input) to the input of the deriving IC than applying (Low input) and then measuring the output voltage and current.

many thanks....
 

Audioguru

Joined Dec 20, 2007
11,248
Does anybody use old fashioned 74xx series TTL logic ICs anymore?
They have a very high supply current even when they are doing nothing.
 
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