clock chip with multiplexed BCD output ?

Discussion in 'Electronic Components' started by Gerry Jacobs, Dec 10, 2003.

  1. Gerry Jacobs

    Gerry Jacobs Guest

    I am intending to build a Nixie clock with the SN74141 as driver for the
    nixies. The 74141 takes BCD as input.

    Is there any clock chip out there which provides BCD output and seperate
    signal pins for each digit to multiplex the BCD output across the four
    digits ?

    All I could find are chips which drive LCDs directly. However output to
    control the LCD/LED segments is not particulary useful since I need BCD
    input.

    I really would like to save the expense to use a microcontroller to do the
    job.

    TIA

    Gerry
    Gerry Jacobs, Dec 10, 2003
    #1
  2. Gerry Jacobs

    Sal Brisindi Guest

    Gerry,
    There were many clock ic's manufactured with BCD outputs but good luck trying
    to find them. The numbers are MM5311, MM5312, MM5313 and I think MM5315. The
    other one is FCM7002 (CT7002) with alarm and calander. There is a decoder chip
    you can use that decodes 7 segment to BCD, that chip is the rare 74C915. but
    you can find it for about $7.00 and use the MM5314 clock ic which is still
    available. Hope this information helps.

    Sal
    www.tuberadios.com/nixie

    Gerry Jacobs wrote:

    > I am intending to build a Nixie clock with the SN74141 as driver for the
    > nixies. The 74141 takes BCD as input.
    >
    > Is there any clock chip out there which provides BCD output and seperate
    > signal pins for each digit to multiplex the BCD output across the four
    > digits ?
    >
    > All I could find are chips which drive LCDs directly. However output to
    > control the LCD/LED segments is not particulary useful since I need BCD
    > input.
    >
    > I really would like to save the expense to use a microcontroller to do the
    > job.
    >
    > TIA
    >
    > Gerry
    Sal Brisindi, Dec 11, 2003
    #2
  3. Gerry Jacobs

    Michael Guest

    Gerry Jacobs wrote:
    >
    > I am intending to build a Nixie clock with the SN74141 as driver for the
    > nixies. The 74141 takes BCD as input.
    >
    > Is there any clock chip out there which provides BCD output and seperate
    > signal pins for each digit to multiplex the BCD output across the four
    > digits ?
    >
    > All I could find are chips which drive LCDs directly. However output to
    > control the LCD/LED segments is not particulary useful since I need BCD
    > input.
    >
    > I really would like to save the expense to use a microcontroller to do the
    > job.
    >
    > TIA
    >
    > Gerry




    Expense? Implement both the clock and the BCD generator with just a
    micro. Since I happen to be a PIC bigot I would use a $2.60 PIC16F628,
    but an Atmel or Motorola or whatever would do just as well.
    Michael, Dec 11, 2003
    #3
  4. Gerry Jacobs

    Sal Brisindi Guest

    Michael,
    I would love to learn how to program am Pic or AVR so I can create my own clock
    ic's. I have a bunch of the Atmel 2313'2 and a developement board, one day I
    have to sit down, read a book and give it a shot.

    Regards,
    Sal

    Michael wrote:

    > Gerry Jacobs wrote:
    > >
    > > I am intending to build a Nixie clock with the SN74141 as driver for the
    > > nixies. The 74141 takes BCD as input.
    > >
    > > Is there any clock chip out there which provides BCD output and seperate
    > > signal pins for each digit to multiplex the BCD output across the four
    > > digits ?
    > >
    > > All I could find are chips which drive LCDs directly. However output to
    > > control the LCD/LED segments is not particulary useful since I need BCD
    > > input.
    > >
    > > I really would like to save the expense to use a microcontroller to do the
    > > job.
    > >
    > > TIA
    > >
    > > Gerry

    >
    > Expense? Implement both the clock and the BCD generator with just a
    > micro. Since I happen to be a PIC bigot I would use a $2.60 PIC16F628,
    > but an Atmel or Motorola or whatever would do just as well.
    Sal Brisindi, Dec 12, 2003
    #4
  5. Gerry Jacobs

    Michael Guest

    Sal Brisindi wrote:
    >
    > Michael,
    > I would love to learn how to program am Pic or AVR so I can create my own clock
    > ic's. I have a bunch of the Atmel 2313'2 and a developement board, one day I
    > have to sit down, read a book and give it a shot.
    >
    > Regards,
    > Sal



    Sounds like you have what you need to get started. Go for it. I think
    you won't regret it. uC's are great little tools; cheap, very capable,
    very flexible. Though the learning curve might be steep - depends on
    the learner's aptitude and capabilities - like anything else worth doing
    it's worth the effort.

    I'm an old guy (50+) who started out with tubes in the early 1960's,
    moved to semiconductors in the late 60's, and to IC's (TTL) in 1969.
    Six years later I started and then finished an EE degree, went to work
    for a major large computer company for 15 years, and only after all of
    that water was under the bridge did I get my feet wet in micros.
    Started with the Z80 in 1994 when the Z80 was all but dead. Quickly
    moved to PICs, the 16F84, then 16F84A, and finally the 16F628. I prefer
    100% assembly language, never use a compiler or interpreter. Assembler
    keeps the mind sharp, in my opinion. ;-)
    Michael, Dec 14, 2003
    #5

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