Emitter Coupled Logic. By preventing the transistor from entering into saturation the high speed operation is achieved in ecl logic family. The design of ecl circuit consists of transistors and resistors.
That is why emitter coupled logic ecl is known as non saturated logic. Ecl uses an overdriven bjt differential amplifier with single ended input and limited emitter current to avoid the saturated fully on region of operation and its slow turn off behavior. As the current is steered between two legs of an emitter coupled pair ecl is sometimes called current steering logic csl current mode logic cml or current switch emitter follower csef logic.
Emitter coupled logic ecl is a bjt based logic family which is generally considered as the fastest logic available.
Emitter coupled logic circuit ecl it has the highest speed of any of the currently available logic circuits. It is primarily due to the fact that transistors never operate fully saturated of cut off. As the current is steered between two legs of an emitter coupled pair ecl is sometimes called current steering logic csl current mode logic cml or current switch emitter follower csef logic. Ecl achieves its high speed operation by employing a relatively small voltage swing and preventing the transistors from entering the saturation region.
