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

Corrosion, I want to know whether the circuits for both methods(linear pola...

I want to know whether the circuits for both methods(linear polarization resistance and electrochemical impedance spectroscopy) are same or not?

Show bandwidth of the system, A communication system for a voice-band (3 kH...

A communication system for a voice-band (3 kHz) channel is designed for a received SNR E b /N 0 at the detector of 30 dB when the transmitter power is Ps =-3 dBW. Find the value o

Compute the load power factor, Considering Figure, let balanced positive-se...

Considering Figure, let balanced positive-sequence, three-phase voltages with ¯V AB = 100√3 0° V (rms) be applied to terminals A, B, and C. The three-phase wye-connected balanced

Draw the equivalent circuits referred to the high-voltage, A single-phase, ...

A single-phase, 50-kVA, 2400:240-V, 60-Hz distribution transformer has the following parameters: Resistance of the 2400-V winding R1 = 0.75 Resistance of the 240-V winding R2

Shunt reactor, what are the basic principles of shunt reactor and it''s ope...

what are the basic principles of shunt reactor and it''s operation system

Electrical machine, Design a suitable double –layer lap winding for a 6-pol...

Design a suitable double –layer lap winding for a 6-pole dc armature with 18 slots and two coil sides per slot. Give values of front-pitch, brack–pitch and commutator pitch. Draw t

Determine downink of a cdma system, Consider the point-to-point radio link ...

Consider the point-to-point radio link introduced in problem 9. By how much must transmit power be increased to maintain the maximum BER of 10-5 if the channel is flat Rayleigh-fad

Fundamental of metal casting, Fundamental of Metal Casting: Fundament...

Fundamental of Metal Casting: Fundamental of Metal Casting : Casting process is based on the property of a liquid to take up the shape of vessel containing it. Molten metal

Discuss mode - 2 of programmable peripheral interface, Discuss mode -2 (bi-...

Discuss mode -2 (bi-directional mode) of 8255 (Programmable Peripheral Interface). Only permitted with port A. Bi-directional bus data used for interfacing two computers and GP

Explain standard set of procedure used in completing a call, Q. Explain Sta...

Q. Explain Standard set of procedure used in Completing a call? Completing a local telephone call between two subscribers linked to the same telephone switch is accomplished 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