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 the synchronous machines, Explain the Synchronous Machines? A s...

Explain the Synchronous Machines? A synchronous machine, unlike an induction (or asynchronous) machine, only develops torque at a fixed, so called, synchronous speed - n s whi

Differences between vga and cga graphics adapters, Q.9 What are the main...

Q.9 What are the main differences between VGA and CGA graphics adapters? Ans: Colour Graphics Adapter (CGA), initially also known as Colour/Graphics Adapter or IBM Colo

What is microprocessor, Write short notes of the following. a)    Microproc...

Write short notes of the following. a)    Microprocessor b)    Modes of data transfer. c)    I/O processor d)    Associative memory e)    Software and Hardware interrupt

Illustrate how to replace the ht fuse, Illustrate how to replace the HT Fus...

Illustrate how to replace the HT Fuse on a 6-pole and 4-pole structure? Ans: a) Open switch on 6-pole or 4-pole. b) Connect the discharge rod between earth and conduc

Define the property under which resistance of metals vanish, The property d...

The property due to which the resistance of some metal or compound vanishes under certain conditions is (A) Semi conductivity.                     (B) Super conductivity.

Cmos integrated circuit design, design using softwares (LEdit7, LTspice) t...

design using softwares (LEdit7, LTspice) the project has many aspects and I would like you to check them on the website with my personal password. in the project specifications (d

Clippers, Which clipper would you prefer between the series and the shunt c...

Which clipper would you prefer between the series and the shunt clipper? Why?

What is the signal classification of 8085, What is the signal classificatio...

What is the signal classification of 8085 All the signals of 8085 can be classified into 6 groups Address bus Data bus Control and status signals Power supply and f

Network theorems.., how to calculate voltage when 3 voltage sources are giv...

how to calculate voltage when 3 voltage sources are given?

Digital circuits, Digital circuits In analog  circuits,  we think  som...

Digital circuits In analog  circuits,  we think  something about  voltages on terminals ranging over natural values.  This provides us the freedom to make an enormous variety

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