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

 

I stopped using old TTL in about 1979 then used only CD4000 series Cmos and 74HCxxxx high speed Cmos ever since.

 

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

 

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...

 

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.

 

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.