Really Quick Question on Enable*

Discussion in 'Homework Help' started by Dorumon, Oct 20, 2009.

  1. Dorumon

    Thread Starter New Member

    Oct 8, 2009
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    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?
     
  2. Jony130

    AAC Fanatic!

    Feb 17, 2009
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  3. Dorumon

    Thread Starter New Member

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

    AAC Fanatic!

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