Connect with us

Replacements for 74LS series

Discussion in 'Datasheets, Manuals and Component Identification' started by JTeach, Oct 8, 2014.

Scroll to continue with content
  1. JTeach

    JTeach

    7
    0
    Oct 6, 2014
    Greetings! I've discovered that our inventory only has the 74 LS series for the basic logic gates. Since these need 5V and the other chips I'm using can run off a 9V battery I'm in need of a different line of ICs. I've heard that CMOS will meet my needs but I can't find the matching part numbers for these:

    74LS08
    74LS04
    74LS00
    74LS02
    74LS86
    74LS32

    If someone happens to know them, or a site where I can easily look them up, your help would be appreciated.

    (I've already looked into using a voltage converter and ruled it out for this particular project).
     
  2. Supercap2F

    Supercap2F

    550
    150
    Mar 22, 2014
    Here's what I could find, it's out of the book "CMOS Cook Book" by Don Lancaster.
    TTLCMOS
    74LS084081
    74LS044009 or 4049
    74LS004011
    74LS024001
    74LS864030
    74LS324071
    I don't know how accurate it is, so you will need to double check.
    Dan​
     
  3. JTeach

    JTeach

    7
    0
    Oct 6, 2014
    Having a place to start is all I need. Thanks Dan!
     
  4. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,299
    2,737
    Jan 21, 2010
    Other alternatives include using a 5V regulator. Even with a regulator you may find that the current draw from TTL (even LS-TTL) is higher than you're happy with.

    74HC series CMOS is also 5V, but operates at much lower current (at least at all but high frequencies).

    74AHC is similar except that it has TTL compatible input voltages.

    In these cases the part numbers you need are easily obtained. 74LS08 -> 74HC08 -> 75AHC08. The pinouts are also the same -- you should check because 4000 series CMOS may not be!

    There are also exotic (or more exotic) logic families with similar names that operate at different voltages. In particular there are low voltage parts which can operate down to 1.8V. Most (but certainly not all) 74xxCxxx CMOS has an absolute max voltage of 7V. This is higher than equivalent TTL, but not high enough to allow you to use your 9V battery. (Also I don't recommend that you play on the edge of "absolute maximums).
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-