What is a darlington pair, Electrical Engineering

Assignment Help:

Q. What is a darlington pair?

                            The Darlington circuit consists of two cascaded emitter followers with infinite emitter resistance in the first stage.here the two transistor form a composite pair, input impedance of the second transistor consisting of the emitter load resistance of the first transistor.

· Darlington emitter follower has high input impedance than the single stage emitter follower.

· Its voltage gain is less close to unity than a single stage emitter follower.

· The output impedance of a darlington circuit may be greater than or less than that of a single transistor emitter follower, depending upon the value of resistance.

· Major drawback of Darlington transistor pair is that the leakage current of the first transistor is amplified by the second; hence the overall leakage current is high. A Darlington pair is two transistors connected together to give a very high current gain. In addition to standard (bipolar junction) transistors, there are field-effect transistors which are usually referred to as FETs.

1806_What is a darlington pair.png

 

The emitter current of Tr1 is the base current of Tr2.

A change in base current of Tr1 can give a change 100 times larger in its emitter current. A change in the base current of Tr2 has a similar effect on its emitter current. Therefore there is an overall amplification of 100 x 100 = 10000 times. This circuit is sometimes called the Super Alpha Pair. It is often used as a power output stage.


Related Discussions:- What is a darlington pair

Amper circuital lw, the plot of amper circuital law by using matlap?

the plot of amper circuital law by using matlap?

Analog signal processing, Derive Equation 13-20 pertaining to the convers...

Derive Equation 13-20 pertaining to the conversion algorithm based on redefined unit capacitor

EEE, ferroelectric materials are charatrised by

ferroelectric materials are charatrised by

Mobile communication, #qConsider a point-to-point radio link between two hi...

#qConsider a point-to-point radio link between two highly directional antennas in a stationary environment. The antennas have antenna gains of 30 dB, distance attenuation is 150 dB

Packet switching over circuit switching, Q. Justify disadvantages and advan...

Q. Justify disadvantages and advantages of packet switching over circuit switching? Ans: Comparison of circuit switching and packet switching showing disadvantages and advan

Determine paper is hygroscopic and absorbent or not, Paper is hygroscopic a...

Paper is hygroscopic and absorbent. This statement is true or false. Ans: Paper is hygroscopic and absorbent. This statement is true.

Explain symmetrical t-attenuator, Question 1 State and Explain Kirchhoff's...

Question 1 State and Explain Kirchhoff's Voltage and Current Law Question 2 State and prove Thevenine's Theorem Question 3 What is a filter? Design a Constant -K band Pa

Direct addressing , Direct Addressing In this  addressing  mode one  o...

Direct Addressing In this  addressing  mode one  of the  operands is the  data stored  in the memory. The memory  address of the  operand is directly  given in the instruction

Ac motors, If the stator windings of an alternator were to be supplied ...

If the stator windings of an alternator were to be supplied by an AC of frequency f (as opposed to drawing an AC current from them as would be the case for an alternator) then

What is autotransformers, Q. What is Autotransformers? In contrast to a...

Q. What is Autotransformers? In contrast to a two-winding transformer, the autotransformer is a single-winding transformer having a tap brought out at an intermediate point. Th

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd