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

Second generation 1954- 1964- history of computer , Second Generation ( 195...

Second Generation ( 1954- 1964) After the invention of semiconductor devices mainly transistors size of computer s was reduced a lot computing power increased reliability was

What is digital system components, Q. What is Digital system components? ...

Q. What is Digital system components? The reason that digital systems are so inexpensive and yet so powerful is that they consist of very  large numbers of just a few building

Opmi]]r., Ask question #Minimukkgkmm 100 words accepted#

Ask question #Minimukkgkmm 100 words accepted#

Find the output voltage in terms of the input voltage, Q. Find the output v...

Q. Find the output voltage in terms of the input voltage? In order to illustrate the insensitivity of feedback circuits to variations of the op-amp parameters, let us consider

Push instruction - stack operations , PUSH Instruction This  instructi...

PUSH Instruction This  instruction copies  the contents  of the specified  register  pair into the  stack. The  contents  of stack  pointer register  are decremented by two. Th

Hall effect, Describe hall effect?also describe it''s mathematical analysis...

Describe hall effect?also describe it''s mathematical analysis and it''s properties

Induction motor, A very widely used alternative form of synchronous motor i...

A very widely used alternative form of synchronous motor is the  ' indu c tion motor'. This has the advantage that it does not require an auxiliary motor to run the rotor up t

Give the properties of pvc, Give the properties of PVC. PVC- It is acqu...

Give the properties of PVC. PVC- It is acquired from polymerisation of hydrogen chloride and acetylene in the presence of a catalyst as peroxides at about 50 0 C. Properties

Asic based new product development project, Assume you are working for an S...

Assume you are working for an SME operating in the microelectronics sector. You are required to plan a new product development project. This is an internal project, so it does not

Output characteristics , Output Characteristics The output  or drain  ...

Output Characteristics The output  or drain  characteristic of N - Channel  power MOSFET. When gate  is made positive with respect to the source an N type  channel  is formed

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