What to do with unused inputs and output on a LM393?

Discussion in 'General Electronics Chat' started by spinnaker, Jan 24, 2017.

  1. spinnaker

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    I have a need for a LM393 where I will only use one comparator. what is the best thing to do with the unused inputs and output? Is it OK to le them float? Tie them high? Low?
     
  2. GopherT

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  3. spinnaker

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    Strange. The datasheet I have from TI does not have an 8.4 and does not mention what to do with the pins.

    Thanks!
     
  4. GopherT

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    Weird that they have multiple versions.
     
  5. spinnaker

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    Mine is SLCS005Y –OCTOBER 1979–REVISED JUNE 2015
    Yours SNOSBJ6F–OCTOBER1999–REVISED DECEMBER 2014

    Looks like mine might be outdated. Wonder why it is still posted?
     
  6. GopherT

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    Yours was updated more recently than mine (far right date). I think mine was for the tin can version of the op amp. The pinout on the example circuit board is round.
     
  7. spinnaker

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    Missed that. It is late and I really should be in bed. I wonder why they did not include that note in the updates??
     
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  8. Banjerd Millionrich

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    Jan 20, 2017
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    do not let them float ,pull them to ground with 1-2 k Resistor.
    if you let them float,in some area with high frequency generating source ,your circuit might be erratic from noise interference.
     
  9. GopherT

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    The data sheet say they should be tied directly to (-) power rail with no resistors.
     
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  10. crutschow

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    Resistors serve no purpose and are not needed.
     
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  11. spinnaker

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    Output is open collector so it certainly shouldn't hurt that. That was going to be one of my follow ups so thanks everyone.
     
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