Re: The 74L72 IC


Jeff W <vwthingy@...>
 

I agree with John, and if I was the original poster, I would first
check the function of this flip-flop and what drives the inputs, and
see if the standard 7472 TTL part would work. It could be that Tek
went with the L version just to save power, and the standard TTL part
would work just fine. If I recall, John is absolutely correct in the
power dissipation ratio between the two families (10:1, 10mW per gate
for TTL, 1 mW per gate for L TTL), however I don't recall that the
input drive current was significantly different between the two. (I
could be waaay wrong on this as it has been 20 years since I last
designed anything with TTL!)

Jeff

John Doran wrote:
Still, I cannot imagine
that one hotter logic chip would load the 'scope's power supply
excessively. The more likely problem is that whatever drives the
74L72's inputs might not be able to handle standard TTL.

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