Compare ttl logic and cmos logic?

The logic functions for both families of devices are the same. They differ only in their performance and other characteristics.

TTL stands for Transistor-Transistor Logic. Advantages include higher speed, better current handling and relative immunity to static discharge. Disadvantages include more power consumption, output high voltage drops and fixed supply voltages (typically 5 volts).

CMOS stands for Complimentary Metal Oxide Semiconductor. Advantages include better voltage output, better input voltage tolerance, variable supply voltages, higher density and much lower power consumption (although this increases with frequency). Disadvantages include sensitivity to static electricity and less current handling capability. Most new product development is in the CMOS family due to its more desirable characteristics.

TTL and CMOS families contain many "sub-families" designed with special characteristics for specific applications. For instance, some CMOS families can handle greater current, function at higher speeds or operate at much lower voltages. Texas Instruments has more than 40 families of products under CMOS and TTL.