CMOS alternative for 74LS112?

Discussion in 'General Electronics Chat' started by electronice123, Jan 27, 2016.

  1. electronice123

    Thread Starter Senior Member

    Oct 10, 2008
    302
    0
    I'm working on simulating a old circuit on multisim and I can't find the IC I need.

    The IC is a 74LS112: Dual J-K Negative edge triggered flip flops with preset and clear

    Anyone know what the CMOS 4XXX equivalent is?

    Any help would be appreciated!
     
  2. Papabravo

    Expert

    Feb 24, 2006
    10,179
    1,799
    I think asked this question about 40 years ago and the answer was -- there isn't an exact substitute in the CD4000 series. I think the closest match in CMOS is the 74HC112. The CD4027 is a JK flip-flop but the truth table has subtle differences.
     
  3. WBahn

    Moderator

    Mar 31, 2012
    17,788
    4,807
    Do you need a CMOS equivalent, or does it specifically have to be a 4000-series CMOS equivalent?
     
  4. electronice123

    Thread Starter Senior Member

    Oct 10, 2008
    302
    0
    I guess not, it just has to work in the 5V range
     
  5. electronice123

    Thread Starter Senior Member

    Oct 10, 2008
    302
    0
    Wow, that is an old chip!
     
  6. Papabravo

    Expert

    Feb 24, 2006
    10,179
    1,799
    It was the dawn of CMOS Integrated Circuits.
     
  7. WBahn

    Moderator

    Mar 31, 2012
    17,788
    4,807
    So will Papabravo's answer work for you?
     
  8. electronice123

    Thread Starter Senior Member

    Oct 10, 2008
    302
    0
    I don't think it will...It needs to be negative edge triggered
     
  9. electronice123

    Thread Starter Senior Member

    Oct 10, 2008
    302
    0
    Could I do the same thing if I added an inverter before and after the flip flop then used the 4027 since it's positive edge triggered?

    Would that give me the same results?
     
  10. ScottWang

    Moderator

    Aug 23, 2012
    4,856
    767
    An IC inverter as CD4069 or an bjt NPN inverter also can do the same job.
     
  11. electronice123

    Thread Starter Senior Member

    Oct 10, 2008
    302
    0
    Cool, thanks, I'll get working on that simulation and see if it works correctly.
     
  12. ScottWang

    Moderator

    Aug 23, 2012
    4,856
    767
    If the frequency is not important then other IC also can used here as 74HC04 is an inverter, 74HC14, MC14584, CD40106 are the Hex Schmitt Triggers, etc,..., it is depends on what kind of IC I have in hand.
     
  13. Techno Tronix

    Member

    Jan 10, 2015
    140
    10
    I think CMOS 4XXX closest match is 74HC112 as papabravo mentioned.
     
  14. Papabravo

    Expert

    Feb 24, 2006
    10,179
    1,799
    The 74HC112 is negative edge triggered, just like the 74LS112.
    If you use the CD4027 pay attention to the "don't cares" in the truth table and observe setup and hold times.
     
  15. WBahn

    Moderator

    Mar 31, 2012
    17,788
    4,807
    But the 74HC112 that Papabravo recommended IS negative-edge triggered.

    Get the data sheets for both the 74LS112 that you are looking to replace and the 74HC112 and compare them.

    If you need it to have TTL compatible I/O, then there is the 74HCT112 to consider, as well.
     
  16. hp1729

    Well-Known Member

    Nov 23, 2015
    1,964
    219
    74ACT11112
    (edited to add ...)
    OOps, nope. Power in the wrong place?
     
Loading...