3-input to 8-output switching

Discussion in 'The Projects Forum' started by mikailgarcia, Aug 17, 2013.

  1. mikailgarcia

    Thread Starter New Member

    Aug 11, 2013
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    0
    hi,

    am building a switching circuit that takes an input from 3 pins (3-bit), run through logic gates and provides a high pin on one of the 8 pins output. this is like a binary to decimal, except that only one of the 8 pins should be high.

    am quite not sure if there is already a post earlier, however, i would need some help from anyone who can point me to the right direction, perhaps some sample circuits.

    thanks a lot!
     
    Last edited: Aug 17, 2013
  2. simo_x

    Member

    Dec 23, 2010
    200
    6
    Hi,

    Are you sure there is not a BCD decimal converter for your needs?

    If not, what about using NMOS (maybe logic level) on each output or just using NOT gate?

    Regards
     
  3. crutschow

    Expert

    Mar 14, 2008
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    You can use a BCD to decimal (or 3-bit binary to 8) converter such as the CD4028.
     
  4. rogs

    Active Member

    Aug 28, 2009
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  5. ScottWang

    Moderator

    Aug 23, 2012
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    If you want a switching using 3 pins to choosing one from eight inputs then it should be CD4051, if you want a decoder then you can using CD4028.
     
  6. rogs

    Active Member

    Aug 28, 2009
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    Not quite sure why posters are recommending a CD4028, which is a BCD to Decimal decoder?
    The OP says in his first post that he only requires 8 outputs, not 10 ?

    A 3 to 8 decoder would seem to fit those specific requirements better....or have I missed something?..
     
  7. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    absf likes this.
  8. ScottWang

    Moderator

    Aug 23, 2012
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    If you go to buy something, the thing cost US$10, and then does it matter what you have are US$10 or $20, but you can't only have $9, is that right?
     
  9. crutschow

    Expert

    Mar 14, 2008
    13,045
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    You can use 3-bits of the 4-bit BCD input to get a 3-bit to 8 output decoder. You just ignore the other input bit and the two extra outputs. So whether a 3 to 8 decoder is better depends upon your definition of "better". ;)
     
  10. simo_x

    Member

    Dec 23, 2010
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    6
    The OP has missed to explain the boolean function (or truth table) he needs. :rolleyes:
     
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