Where are the 7400 series chips now?

Discussion in 'General Electronics Chat' started by jcyang, Jan 18, 2010.

  1. jcyang

    Thread Starter New Member

    Jan 18, 2010
    Do engineers still use 7400 series chips now?Or they are only for education now?

    If there are still alive,whats the usage of these chips?

  2. bertus


    Apr 5, 2008
  3. Wendy


    Mar 24, 2008
    I learned TTL when I was in college, but the fact they take 5V is pretty limiting. The CMOS CD4000 and 4500 series are more open ended.

    All of these are obsolete more or less, so there will be some chips you simply can not get.
  4. steveb

    Senior Member

    Jul 3, 2008
    Agree with the above statements.

    To directly answer your title question "Where are the 7400 series chips now?" ....

    A good number of them are in plastic drawers in my lab, and there they will remain until my heirs throw them away at some distant (I hope) time in the future.
  5. rjenkins

    AAC Fanatic!

    Nov 6, 2005
    The original 74 Series devices are pretty much obselete, however the 74LS, 74ALS & 74ACT series are still very useful when building medium scale microprocessor based systems.

    What else do you use for data buffers, address decoders etc?

    (The 4000 series are very slow by comparison and not really suitable for this type of job).

    Many current PC motherboards and the more complex I/O cards still use 74xx series devices.
  6. SgtWookie


    Jul 17, 2007
    The original 54/74 series IC's made good room heaters. :eek: However, they were a quantum leap ahead of using discrete components.

    You still see them used occasionally for various things, usually something like port expanders for a low pin-count uC or the like.

    However, with the availability of inexpensive uC's that can be re-programmed on the fly, using a bunch of TTL IC's just isn't cost effective anymore. Board space (PCB) is expensive; re-designs are prohibitively expensive.
  7. BMorse

    AAC Fanatic!

    Sep 26, 2009
    We might be the only ones still using 7400 series in our products (commercial/Industrial machinery), we use a lot of them mostly for buffers, and for our DC Motor control modules.......

    Here is pic of a 2 Speed DC Motor control PCB that we use the 74LS08, 74LS00, 74LS139, and the 74LS04 on......

    7400LS series.jpg
  8. Bernard


    Aug 7, 2008
    Go back to the 1960's, a dual FF using a hand-full of 2N 404's, took a 5X5 card; big jump to resistor-transietor-logic,RTL, with a verry short life. Quantum jump to transistor-transistor-logic, TTL, which in its variants, is still in limited use today. For a 100 school alarm system,early 1970s I was forced to use TTL because RCA had only a few CMOS [ my favorite ] packages were available. I still have about 80 TTLs available to one & all for just postage.
  9. cumesoftware

    Senior Member

    Apr 27, 2007
    Nowadays you can replace the entire 7400 series using the 74LS series, or even the 74HC/74HCT series, except for a few chips.