Digital Electronics - Digital Concepts - Discussion

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 (e.g. , AND) and the amplifying function are performed by transistors (contrast with RTL and DTL).

TTL is notable for being a widespread integrated circuit (IC) family used in many applications such as computers, industrial controls, test equipment and instrumentation, consumer electronics.

Bipolar has two poles meaning that positve and negative. Transistor has two poles calles pn and pn for pnp transistor and np pn for npn transistor. Both transistor operates in forward and reverse bias so TTL is the answer of that question.

Two types of operations in bipolar ICs.

1. Saturated
2. Non-Saturated.

Saturated bipolar logic family.
* RTL
* DCTL
* IIL
* DTL
* HTL
* TTL

Non-saturated family.

* Schottky TTL
* ECL

TTL - Transistor - Transistor logic.

LSI - Large scale integration circuits.

CMOS - Complementary metal oxide semiconductor.

NMOS - N - Type metal oxide semiconductor.

When ever we are using cmos we have to use FET (FIELD EFFECT TRANSISTOR). Cmos is nothing but combination of PMOS and NMOS.

The CMOS uses a complementary-symmetry metal oxide semiconductors they are field effect p,n type transistors.

Using bipolar transistor in digital technology is called Transistor Transistor Logic (TTL).

CMOS - complementary metal oxide semiconductor it consumes less power.

LSI means Large Scale Integration words related to IC chip design.

TTL uses Bipolar Junction Transistor. CMOS uses MOSFET.