What is ECL operation?

What is ECL operation?

Operation. The ECL circuit operation is considered below with assumption that the input voltage is applied to T1 base, while T2 input is unused or a logical “0” is applied. During the transition, the core of the circuit – the emitter-coupled pair (T1 and T3) – acts as a differential amplifier with single-ended input.

What are the characteristics of emitter coupled logic?

Inverter circuit of emitter-coupled logic It has two NPN transistors connected in differential single-ended input mode. Both the emitters are connected together with common resistance RE. It is a current limiting resistance, used to prevent the transistor from entering into saturation.

What is the major advantage of ECL logic?

Following points summarize ECL advantages over TTL and CMOS: ➨It has fanout of 25 which is better than TTL and less then CMOS. ➨It has average propagation delay time ( 1 to 4 ns ) better compare to both TTL and CMOS. Hence it is known as fastest logic family.

What is the difference between transistor logic and emitter coupled logic?

TTL (Transistor Transistor Logic) IC technology uses bipolar transistor as principal circuit element. CMOS (Complementary Metal Oxide Semiconductor) IC technology uses FET as principal circuit element. ECL (Emitter Coupled Logic) IC technology uses bipolar transistors configured as differential amplifier.

Why ECL has least propagation delay?

(a) ECL which has a propagation delay at 2ns. It is an old technology and the speed is due to the fact that the transistors never enter saturation — so there is no time to wait for the transistor to come out of saturation.

What is ECL family?

Emitter-Coupled Logic (ECL): The ECL family is the fastest logic family in the group of bipolar logic families. The characteristic features that give this logic family its high speed or short propagation delay are outlined as follows: It is a nonsaturating logic.

What is ECL signal?

Emitter Coupled Logic (ECL), sometimes referred to as Current Mode Logic, is an extremely high-speed digital technology. ECL has a propagation time of 0.5 – 2 ns, which is much faster than TTL. However, its power dissipation is three to 10 times higher than that of TTL.

Why ECL is fastest logic justify?

Explanation: ECL is the fastest of all the logic families because of the emitters of many transistors are coupled together which results in the highest transmission rate.

Why ECL is the fastest logic family?

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).

What is the noise immunity of ECL family?

It has excellent noise immunity amongst all families. A logic high voltage for ECL is somewhere between 4.5V to 5V. The propagation delay is the worst when compared with TTL and ECL families at about 200ns.

Which TTL family is fastest?

Emitter-coupled-logic (ECL) is a BJT logic family that is generally considered the fastest logic available.

What is CMOS circuit?

CMOS is an integrated circuit built on a printed circuit board, a widely used kind of semiconductor used in transistors. It is a battery-powered memory chip that effortlessly holds the initialization data and the BIOS uses this data to turn on the device, that is during the bootup process.