What are the advantages of transistor-transistor logic?

Answer 1

Transistor-transistor logic (TTL) is a class of digital circuits built from bipolar junction transistors (BJT) and resistors. It is called transistor-transistor logic because both the logic gating function and the amplifying function are done by transistors.

To know about the advantages of TTL logic family, one should have a basic idea about RTL, DTL etc. Diode logic (DL) uses diodes to implement logical functions like AND and OR. But the disadvantage is that it can not perform NOT operation. As AND and OR are not complete functions by themselves, they can not perform several logic functions without NOT. Hence, there was a need for some device which can perform a NOT function as diodes can not. That device is a transistor. Then came the DTL which uses a transistor along with diodes. As a transistor can act as an inverter, NAND (NOT-AND) & NOR (NOT-OR) operations can be performed. But this logic uses several diodes which will slow down its operation. Due to the delay offered by them, the logic levels may sometimes change i. e. 0 t0 1 or 1 to 0. Then came TTL. This logic uses a multi emitter transistor, a transistor with many emitter terminals. As every emitter is nothing but a diode, this logic eliminates the use of all diodes. This is the major advantage. As transistor becomes ON and OFF much rapidly than a diode, switching time will be faster.

TTL, or Transistor-transistor logic replaced resistor-transistor logic, and used much less power. The TTL family is very fast and reliable, and newer faster, less power-consuming, etc. types are always being developed.

ANSWER: ONE WORD SPEED

Answer 2

1. Speed, when compared to the previous RTL and DTL.

2. More complex circuitry, compared to RTL/DTL.

3. Smaller packages compared to RTL/DTL.

4. Depending on type, lower power consumption than RTL/DTL.