Explain working of bipolar junction transistors, Electrical Engineering

Assignment Help:

Q. Explain working of Bipolar junction transistors?

The family of bipolar junction transistors has two members: the npn BJT and the pnp BJT. Both types contain semiconductor junctions which operate with bipolar internal currents consisting of holes and electrons. These are illustrated in Figure along with their circuit symbols.

1371_Bipolar junction transistors.png

The emitter in the circuit symbol is identi?ed by the lead having the arrowhead. The arrow points in the direction of conventional emitter current ?ow when the base-emitter junction is forward biased. A transistor can operate in three modes: cutoff, saturation, and active. In the active mode, for an npn BJT, the base-emitter junction (BEJ) is forward-biased by a voltage vBE, while the collector-base junction (CBJ) is reverse-biased by a voltage vCB. Thus for an npn BJT, as shown in Figure (a), iB and iC are positive quantities such that iB + iC = iE. For a pnp BJT on the other hand, in the active region, the base-emitter and collector-base voltages are negative, and  currents iB, iC, and iE are all negative quantities such that iE = iB + iC, that is to say, the bias voltages as well as current directions are reversed compared to those of an npn BJT.


Related Discussions:- Explain working of bipolar junction transistors

Determine the speed at which the machine runs as a motor, A 100-kW, dc shun...

A 100-kW, dc shunt generator, connected to a 220-V main, is belt-driven at 300 r/min, when the belt suddenly breaks and the machine continues to run as a motor, taking 10 kW from t

Saturation and cutoff in bipolar junction transistor, Saturation and Cutoff...

Saturation and Cutoff in bipolar junction transistor: Saturation : With both of the junctions forward-biased, a BJT is in saturation mode and makes easy high current condu

Sub threshold, Sub Threshold The sub threshold I-V curve depends expon...

Sub Threshold The sub threshold I-V curve depends exponentially on the threshold voltage, introducing a strong reliance on any manufacturing variation that influences threshol

If a feeder circuit-breaker trips what action is required, Q. If a feeder c...

Q. If a feeder circuit-breaker trips, what action is needed? Ans: First isolate the faulty feeder check the faulty area on which fault the breaker was tripped (open circuit,

What is a clipper circuit, Q. What is a clipper circuit? Clipping circu...

Q. What is a clipper circuit? Clipping circuits are linear wave shaping circuits. The main function of 'clipper' is that it clips off a part of input waveform i.e., it cut off

Explain in brief about the robots, Explain In brief about the Robots - ...

Explain In brief about the Robots - Robot is programmed with a series of instructions that enable it to carry out a series of tasks - On the other hand, an operator manually

Process , Process The rectangle symbol  is used to represent  the pro...

Process The rectangle symbol  is used to represent  the process  operations as shown below.   MOV A, B

Doping, expalin process of doping how to do doping

expalin process of doping how to do doping

Explain the different types of polarizations, Explain the different types o...

Explain the different types of polarizations. Polarizations are of three types. i. Electric polarization ii. Ionic polarization. iii. Dipolar polarization.

Probability assignment, how probability help in the field of electrical tel...

how probability help in the field of electrical telecommunication engineering?

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