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

Electricity and gas hazards, INTRODUCTION : Electricity is one of the fine...

INTRODUCTION : Electricity is one of the finest gifts of science to the mankind since just a flick of switch can flood the room with light or put on a fan, an air conditioner or a

Case 1 b>a - program description , Case 1 (B>A) Suppose XX = 01H ( s...

Case 1 (B>A) Suppose XX = 01H ( stored in a) and YY = 03H (stored  in B).then carry flag  will set by  CMP  instruction since B>A  in this case JNC  will not  transfer the e

Half wave rectifier connected to a dc motor, Ask questiwe have half wave re...

Ask questiwe have half wave rectifier connected to a dc motor load. by using a step down transformer from 8 to 1. by modalization we have the Primary Winding resistance is Rp=50 oh

555 timer ic, i wanted the exact names of the components of the internal ci...

i wanted the exact names of the components of the internal circuit of a 555 timer ic

Find the resistor values of rc, Apply the rule-of-thumb dc design presented...

Apply the rule-of-thumb dc design presented in this section for a silicon npn BJT with β = 70 when the operating Q point is defined by I CQ = 15 mA and I BQ = 0.3 mA, with a dc s

Evaluate maximum directive gain, Q. For a pyramidal-horn antenna, the maxim...

Q. For a pyramidal-horn antenna, the maximum directive gain is given by occurring when the aperture dimensions are A ∼ = √3λLandB = 0.81A. The principal-plane beam- widths

Sketch the depletion mosfet drain characteristics, Q. Sketch the depletion ...

Q. Sketch the depletion MOSFET drain characteristics The depletion-type MOSFET has a structure similar to that of the enhancement-type MOSFET with one important difference: The

Metal–oxide–semiconductor structure, Metal-Oxide-Semiconductor Structure ...

Metal-Oxide-Semiconductor Structure A traditional metal-oxide-semiconductor abbreviated as MOS structure is acquired by growing a layer of silicon dioxide (SiO 2 ) on top of

For parity flag - return instructions , For Parity Flag PRE ( Return ...

For Parity Flag PRE ( Return on Parity Even)  and RPO ( Return on Parity Odd) Instructions RPE returns from the  subroutine to the  calling  program if parity flag is not s

Calulation of hv/lv ratio to reduce the line loss, kindly send us the formu...

kindly send us the formula and C program for performance improvement of distribution system using HV/LV ratio. REGARDS ANUJ AGARWALA

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