Really Quick Question on Enable*

Thread Starter

Dorumon

Joined Oct 8, 2009
24
I couldn't find this in the DataSheet. But what happens when an Enable* is not connected to a logic 0 or 1? The DataSheets usually only state the circuit's behaviour when its set to voltage High or low, but what happens when its not connected at all?

I am working on a 74LS151 Multiplexer here, but I dun think the circuit matters in this questions, I just need a general answer. I know the main output will be logic 0. but I haven't tried and can't try at the moment the complement output's logic, but I suspect is 0 because since nothing is connected the device is completed shutdown?
 

Jony130

Joined Feb 17, 2009
4,930

Thread Starter

Dorumon

Joined Oct 8, 2009
24
Well, I connected the device and got an logic 0, I believe I am using TTL, is the output wrong?
 

studiot

Joined Nov 9, 2007
5,003
It has always been considered bad practice to leave inputs floating. They should be tied high or low as appropriate.
 
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