- A technology used to produce logical functions, which uses transistors to provide those functions.
A popular series (or "family") of TTL logic integrated circuits is the 74xxxx ("seventy-four hundred") series. This series of chips also has a military grade implementation that is numbered exactly the same, but with a '54' prefix in place of the '74' prefix.
More recently, the 74xxxx series of TTL logic chips have been re-implemented using CMOS
technology. The series is named 74HC
xxx. The 'HC' signifies "H
The chips in the HC series have the exact same functionality and pin-outs as the TTL series, but with the advantages afforded by being implemented in CMOS
(such as lower power consumption and very high input impedance).