[2017] detail guide of the emitter coupled logic

what is switching devices ?

emitter coupled logic is the high end electronics switching devices integrated circuit logic.this is most important for the high speed electronics device operation.

Name is indicated that the emitter coupled logic has emitter is common terminal and the other is connected to the circuit..

 what is switching devices ?

in the operation of the any quatity there are only two typr of switching device is provided 

1) mechanical switching device

2) electronics switching device

mechanical switches has many disadvantage like it has friction and many losses occur in the system.

as compare to the mechanical switches electronics switches as many advantage like smooth operation.

and also not any friction and drop of any losses

fast operate

less time consuming

so most of operation in the industrious control by the electronics switch are used.  

in this electronics switch used element is like 


- Transistor

- Emitter coupled logic

- Triode


- Turn off thyristor

- Thyristor


here we introduce basic knowledge about the emitter coupled logic 

basic of emitter coupled logic

emitter coupled logic is the principle of operation of the electronics switching devices.

it is also known as the ECL as the emitter coupled logic.

in this emitter coupled logic emitter is common terminal so called it is as emitter coupled logic circuit.

electronics devices are also used in the AC to DC converter as a rectifier switches.

all of the device MOSFET is the fastest electronics devices allover others.

MOSFET is the four terminal devices..

only use for fastest application where required.

ECL is bipolar transistor.ECL is used for the bipolar differential amplifier.it has the slow turn off behavior.

it is also called as some other name are like current steering logic (CSL) , Current mode logic (CML) , current switch emitter follower (CSEF) logic.

we know that the it has its input impedance is high and its output impedance is low.


Basic Circuit Diagram of emitter coupled logic(ECL)

this is the circuit diagram of the emitter coupled logic.

shown in the figure then you will find three no of the transistor in the middle of the circuit.

and one register Re  which is connected between the emitter and common terminal so it called as the emitter coupled logic.

in the other Logic part of the circuit registor Rc1 and Rc3 are connected.

both the side of the circuit booster circuit are connected.

Advantage of emitter coupled logic  

transistor never saturated

storage delay of the ECL are eliminated.

here is the propagation delay is minimum so speed is high.it is the fastest switches among the all other.

Due to low output impedance, fan out is large.

ECL logic circuit produces an output and its complement.this is eliminates the need of the inverters
current through Re is more or less constant.so no noise spikes will be generated like those produced by TTL totem-pole circuits. 


 Disadvantages of emitter coupled logic(ECL)

its logic level is soo close so that it has low noise margin around 0.25 v.so ECL circuits are not  suitable for heavy industrial environment.

  • It requires relatively large silicon area and high cost.

  • High power dissipation, Pd= 40mw
  •  Due to high current, there is a problem to dissipates heat due to I^2R drops.

  • this is best guide which is help you to take detail information about the emitter coupled guide.

    thanks for the read this [2017] detail guide of the emitter coupled logic ..

    for more detail shown in below video...as reference..

    thanks again


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