Modern TTL 74 Families

Discussion in 'General Electronics Chat' started by jsthomps, Oct 7, 2012.

  1. jsthomps

    Thread Starter Member

    Mar 30, 2010
    15
    0
    Hi,
    I used to play with with logic circuits way back in the 70's where I used TTL 74, 74L, and 74LS. I would like to get back into the hobby but now there are so many more TTL families. What type should I be using now?
    Regards,
    Scott
     
  2. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    I stopped using old TTL in about 1979 then used only CD4000 series Cmos and 74HCxxxx high speed Cmos ever since.
     
  3. bertus

    Administrator

    Apr 5, 2008
    15,645
    2,344
    Hello,

    The old TTL chips are consuming quite a lot of current.
    The CMOS chips, like the 4000 series are much more economical in power consumption.
    Here is an over view of both series:
    http://en.wikipedia.org/wiki/List_of_7400_series_integrated_circuits
    http://en.wikipedia.org/wiki/List_of_4000_series_integrated_circuits

    More info on digital circuits can be found on these pages of the EDUCYPEDIA:
    Arithmetic circuits
    CMOS technology
    Codes & decoders
    Converters
    Counters & registers
    DAC/ADC types
    Digital logic
    Digital theory

    Flip flops
    FPGA Design
    Memory
    Number systems
    Sigma Delta Conversion
    Technology
    Timers & oscillators
    TTL technology

    Bertus
     
  4. Wendy

    Moderator

    Mar 24, 2008
    20,764
    2,535
    I have to agree, in every measurable way except two CMOS is better. They come in the 4000 and 4500 families. A website I really like is Sam's Electronic Circuits, because it groups a bunch of data sheets together.

    The two ways CMOS is worse? ESD, it is much more sensitive to static damage. You can blow TTL out too, but it is a little harder. The other is drive. CMOS goes rail to rail on the voltage levels, and can take 3-15V (sometimes more), but it has trouble driving a LED (though it can under certain circumstances). I generally use this circuit if I need to light a LED...

    [​IMG]
     
  5. MrChips

    Moderator

    Oct 2, 2009
    12,418
    3,355
    It really depends on what your objectives are. Rather than being driven by the technology, I would focus on the project. Find something that you want to build and then choose the suitable technology. In many cases the problem can be solved with a single microcontroller chip that would cost a fraction of the price of a bunch of CMOS or TTL chips.

    State your project and come back for advice.
     
  6. Wendy

    Moderator

    Mar 24, 2008
    20,764
    2,535
    The one think I really like about CMOS is I can use almost every battery pack off the shelf. For the various projects I wire this is a major plus, you can find my published circuits in the AAC experiments section, in the 555 part. Batteries are easier to use than a plug in power supply IMO.

    Overall CMOS is just less picky. They also have some interesting block diagram chips too.
     
Loading...