Connect with us

Classic Chips

Discussion in 'Electronic Design' started by Paul Burridge, Aug 28, 2003.

Scroll to continue with content
  1. Hi all,

    I've been following the discussion on the thread about chips that have
    been around for 30 years and was just wondering if anyone would care
    to nominate their favourite 'classic chip' of all time. For example
    the chip that they believe deserves, for whatever reason, to be marked
    out as being of exceptional merit or usefulness.

  2. For me, it would probably be a runoff between the 723 voltage regulator and
    the 741 op amp. Both have a great deal of flexibility and have survived ages.
    You can make almost anything with them.


    Chip Shults
    My robotics, space and CGI web page -
  3. 723, 741

    add the 555

    Wouter van Ooijen

    -- ------------------------------------
    PICmicro chips, programmers, consulting
  4. ELAL

    ELAL Guest

    I'd nominate the 555 (and its siamese twin brother 556).
    Can you name any IC that matches both its simplicty AND versatility?
  5. John Jardine

    John Jardine Guest

    Undoubtably the LM393.
  6. I agree. I've used the LM324 (and it's half-brother the LM358) more in
    new designs than the others (the most recently for an NiMH charger
    current sink in a portable instrument). The 1mA it draws didn't matter
    in this case. I can't think of why I'd use a uA741. I used the uA723 a
    decade or so ago in a product and it would still be the right decision
    if a similar problem (programmable linear power module for pressure
    tranducers, process transmitters etc.) if the same problem came up
    today. I still have some TO-99 uA709As around (with a different
    Toshiba part number) used for repairing old temperature controllers.

    The 4558 is also very popular for low-end audio (it's something like a
    dual LM741). Back before good op-amps got cheap I built a
    computer-controlled test rig to screen hundreds at a time for
    temperature drift. I designed a circuit that used two 4558's, only one
    of which was critical, and the yield was always such that there was no

    Best regards,
    Spehro Pefhany
  7. John Larkin

    John Larkin Guest


  8. Jim Thompson

    Jim Thompson Guest

    My G-job work-horses are the LM324 and the LM339... you can build
    almost anything with those two devices. (I can even build a 555
    equivalent ;-)

    ...Jim Thompson
  9. Mark

    Mark Guest

    For me it would be the 4046 PLL.

  10. Jim Thompson

    Jim Thompson Guest

    My design of the MC4024/MC4044 was first ;-)

    ...Jim Thompson
  11. Wait a minute.

    Was it a "7805" when introduced? I remember coming across the LM309
    first, which was of course a 3-terminal 5volt regulator, and maybe
    specifically in a TO-3 package (and a lower current TO-5). National
    had other voltage regulators in their line, with the LM340-XX designator
    (where XX was the actual voltage), which I don't know if they came after
    the 309 or I simply heard of them a tad later. They were available in TO-3
    and TO-220 packages. And what never quite made sense, there was a 5V
    version too.

    A 1972 National databook does not show a "7805", but I can't remember if
    anyone else would have used that designator before National.

    Admittedly, there seems to be a few differences in the internal circuitry
    between the 309 and the 340-XX line, but surely the usefulness of
    the three terminal regulator dates from when it was first succesfully

    (Someone did have a 3-terminal regulator in the sixties, maybe about
    1968, but it was from an obscure manufacturer and I saw only one
    reference to it.)

  12. Somewhere around, I have a clipping from Electronics magazine of
    a circuit sent in by a reader for making a faster 4044 out of
    discrete gates. I don't think it was ECL, more like 74AS, but
    it's been a while since I last looked at it.

    I wouldn't deny the importance of the 4044, but I suspect
    the 4046 despite it's frequency limitations, was a more general
    device. After all, with the built in VCO it could be use where
    a simple PLL was required (as long as in the low frequency range)
    and that VCO meant that it fit into lots of uses where people merely
    wanted a simple oscillator or VCO, tossing aside the phase comparator.

    Then of course, there was that Signetics line of analog PLLs, the 565,
    560, 561 and such. I'm not sure how much commercial use they saw, but
    they made a wave when they first came out in hobby circles, "wow, we
    can now have a PLL in a single package". Never mind that the analog
    phase detector wasn't the best choice for some of the circuits.

  13. 74HC14... Makes a swell schmitt triger, oscillator, monostable, inverter,
  14. Paul:

    I nominate:

    1488/1489 RS-232 drivers and recievers. They "bridge" the analog and
    digital worlds.

    If you could count the number of RS-232 ports shipped over the past 30
    years, each such port contains at least 2 each and often more, it probably
    totals in the billions. i.e. every modem had at least one, every
    multiplexer had 8 or more, often up to 256, every router, every computer,
    every bridge, etc... had at least one, often many, and each generation of
    modem, mux, computer, router, bridge, etc... appeared and was shipped to
    replace the older ones that were junked.

    I'm willing to bet a few bucks that there have been more 1488/1489 chips
    [and their equivalents] than any other chip.

    Thoughts, comments?
  15. I've been following the discussion on the thread about chips that have

    I nominate the RCA CD4057A COS/MOS LSI 4-bit arithmetic logic unit. That
    was a 4-bit slice of computer brains that not only included the ALU, but
    also a 4-bit shift/storage register and an arithmetic overflow flip-flop to
    boot. The interesting thing about the 4057, though, was that it had 2
    control lines that allowed the chip to function as any 4-bit section of a
    larger ALU, or even as a separable section of a larger ALU. With four of
    these babies, for example, you could build a computer that was dynamically
    changeable into a 16-bit machine, a 12-bit and a 4-bit machine, or two 8-bit
    machines. Oh, the power! Oh, the flexibility! Oh, the elegance! (Oh, the
    impenetrable complexity!)

    My second favorite is Motorola's MC14500B Industrial Control Unit, a
    single-bit computer. No, not a single-chip computer (far from it), a
    single-bit computer. Ayup. They were just the thing for replacing relay
    tree logic with chips - that would then drive output relays.

    Please note that the given acceptance qualification for a 'classic chip' is
    that it be of exceptional merit OR exceptional usefulness. Both criteria
    need not apply, and there is nothing to say that a 'classic chip' can't be
    long gone and forgotten. And while the magnitude of the exceptional merit
    vector of the above chips is unquestionable, there is perhaps the matter of
    that vector's sign...

    Also, please note that the acceptance qualification says nothing about a
    'classic chip' being one of those funny analogalisticous things. But if you
    insist on that sort of stuff, I nominate the National Semiconductor LM373
    AM/FM/SSB IF strip. Supposedly, it could do AM, CW, SSB or FM detection,
    and was intended for everything in communications. Unfortunately, contrary
    to National application note AN-54 (April 1972, in the 1973 "Linear
    Applications Handbook 1"), or linear brief LB-13 (November 1970, same
    place), or a dimly-remembered article in an old "Ham Radio" magazine
    somewhere, I don't think anyone actually ever got a circuit based on the
    chip to work.
  16. Jim Thompson

    Jim Thompson Guest


    Absolutely wonderful set of chips...

    Particularly since I designed them ;-)

    ...Jim Thompson
  17. Leon Heller

    Leon Heller Guest

    I got a couple and played around with them when they first came out. IIRC I
    got one working OK for AM. For SSB I think I had problems with the CIO
    leaking into the input and swamping it. It was a long time ago, though.

    The Plessey RF and IF amplifiers (612 etc.) were nice chips.

  18. kansas_ray

    kansas_ray Guest

    Hi Jim,

    Would you give us some history? Why did the 4046 become the "de-facto"? It
    would give us outsiders (and youngsters) some insight.

    Best regards,
  19. Mike Diack

    Mike Diack Guest

    If imitation is the sincerest form of flattery then surely the Intel
    8031 deserves honorable mention.
  20. Jim Thompson

    Jim Thompson Guest

    What's really distressing is that those were "accidental" designs...
    wasn't in my department (I was A-D-A at the time). Young buck
    engineer comes by one afternoon and says "I have a problem", and I
    sketched them both out on the back of an envelope.

    (For Win's information... the driver uses lateral PNPs.)

    ...Jim Thompson
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