ECL):Emitter-coupled-logic (ECL) is a BJT logic family that is generally considered the fastest logic available.ECL achieves its high-speed operation by employing a relatively SMALL VOLTAGE swing and preventing the transistors from entering the saturation region. (Reduces the storage delay TIME).ECL transistor uses differential amplifier configuration as shown: Logic FamilyFull NameAdvantagesDisadvantagesCMOSComplementary metal-oxide-semiconductor1) Lowest POWER consumption2) Used in all microcomputer chips today.3) Most common logic family.Easily damaged by static discharge and voltage spikes.TTLTransistor-transistor logic1) Earliest developed.2) Most rugged.3) Least susceptible to electrical damage.Consumes more power than CMOS – not suitable for battery-operated devices.ECLEmitter-coupled logicFastest available logic familyConsumes more power than CMOS. It requires extreme care in the wiring.