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

Explain about stored program control, Q. Explain about Stored Program Contr...

Q. Explain about Stored Program Control? Stored Program Control:   In centralized control, all control equipment is replaced by a single processor which should be quite powerf

Combinational logic circuit design, Design a circuit to enable a chemical a...

Design a circuit to enable a chemical additive to be introduced into the fluid through another inlet only when the temperature is not too cold or too hot and the fluid is above the

Digital electronics, Design a recycling MOD 19 up counter using JK FFs. In ...

Design a recycling MOD 19 up counter using JK FFs. In your design, include the logic circuit diagram and the timing diagram output that counts from 000002 = 010 to 100112 = 1910. C

Write notes on clamping, Q. Write notes on clamping ? Clamping network ...

Q. Write notes on clamping ? Clamping network shifts (clamps) a signal to a different d.c level, that is it introduces a d.c. level to an a.c signal. Hence, the clamping networ

Working of self - excited generators, Q. Working of self - excited generato...

Q. Working of self - excited generators? For self-excited generators, residual magnetism must be present in the ferromagnetic circuit of the machine in order to start the self-

Issues for installation of meters, Issues for Installation of Meters T...

Issues for Installation of Meters The subsequent should also be ensured: a) Appropriate crimping device should be used for crimping the lugs. Thimbles should be of appro

Objectives of electricity and gas hazards, Objectives After studying th...

Objectives After studying this unit, you should be able to: 1. Describe the consequences of passing electric current through human body, 2. State and recognise the colour

Evaluate a single-stage transistor amplifier, Design and using Pspice, eval...

Design and using Pspice, evaluate a single-stage transistor amplifier amplifier to meet the following specifications: * Power supply - 12V dc. · *Voltage gain - 120 when Vin

Commercial television broadcasting, Commercial television broadcasting is a...

Commercial television broadcasting is allocated frequencies that fall in the VHF and UHF bands. Table lists the television channel allocations in the United States, with the channe

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