reset logic

Discussion in 'General Electronics Chat' started by kvsingh21, Nov 12, 2008.

  1. kvsingh21

    Thread Starter Active Member

    Apr 15, 2008
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    i need some logic that can force the output to zero when the reset signal is active high. I was thinking about nand gate, but its output is active high even when the input is slow. I need something that gives output only when both input and reset are high.
     
  2. mik3

    Senior Member

    Feb 4, 2008
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    Use an AND gate whose output is high only when both inputs are high.
     
  3. kvsingh21

    Thread Starter Active Member

    Apr 15, 2008
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    No what i need is output to be high ONLY when the reset is low and input is high.
     
  4. mik3

    Senior Member

    Feb 4, 2008
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    Use a XOR gate then.
     
  5. kvsingh21

    Thread Starter Active Member

    Apr 15, 2008
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    XOR gives output high when input is low and reset is high. i want the output to be low in this case.
     
  6. kvsingh21

    Thread Starter Active Member

    Apr 15, 2008
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    RESET --IN --OUTPUT
    --0----- 0----- 0
    --0 -----1 -----1
    --1----- 0 -----0
    --1 -----1 -----0


    This is what i actually want.
     
  7. mik3

    Senior Member

    Feb 4, 2008
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    Ok, use an AND gate and connect to one of its input a NOT gate. The Reset input will be on the NOT gate and the other input of the AND gate will be the In input.
     
  8. kvsingh21

    Thread Starter Active Member

    Apr 15, 2008
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    Thanks alot mate.
    Ideally i would like comination of nand and inverters in any order. Any ideas?
     
  9. mik3

    Senior Member

    Feb 4, 2008
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    To implement an AND gate with NANDs take a NAND gate and connect its output to the input of a NOT gate and take your circuit output from the output of the NOT gate.
     
  10. kvsingh21

    Thread Starter Active Member

    Apr 15, 2008
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    Thanks a lot mate. I will give it a try!!!
     
  11. mik3

    Senior Member

    Feb 4, 2008
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    If you want you can use only quad NAND gates IC and implement your logic function. In this way you wont need to put another IC which contains NOT gates on your PCB. Do do it replace each NOT gate mentioned until now with a NAND gate with its inputs connected together.
     
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