Storage delay and transistor alpha- beta, Electrical Engineering

Assignment Help:

Turn-on, turn-off, and storage delay:

The Bipolar transistor shows a few delay characteristics while turning on and off. Most of the transistors, and particularly power transistors, show long base storage time that limits maximum frequency of operation in switching applications. One technique for reducing this storage time is using a Baker clamp.

Transistor 'alpha' and 'beta':

The proportion of electrons capable to cross the base and reach the collector is a measure of the BJT (bipolar junction transistor) efficiency. The heavy doping of the emitter region and light doping of the base region origin several electrons to be injected from the emitter into the base than as compared to the holes to be injected from the base into the emitter. The common-emitter current gain is presented by βF or hfe; it is approximately the ratio of the DC collector current to the DC (direct current) base current in forward-active region. It is generally greater than 100 for small-signal transistors but can be smaller in transistors intended for high-power applications. An additional significant parameter is the common-base current gain, αF. The common-base current gain is almost the gain of current from emitter to collector in the forward-active region. This ratio generally has a value that is close to unity; approximately between the 0.98 and 0.998. Alpha and beta are more precisely related through the following identities (NPN transistor):

αF = Ic/IE

βF = Ic/IB

βF = αF / (1- αF) ↔ αF = βF / (βF +1)


Related Discussions:- Storage delay and transistor alpha- beta

Calculate the sending end voltage, A 150 km long, 3-phase, 400 kV overhead ...

A 150 km long, 3-phase, 400 kV overhead line is used to transmit 1800 MW to a distribution area at 0.9 power factor lagging. The line parameters per phase and per unit length in st

Give an introductive notes about fet amplifier, Q. Give an introductive not...

Q. Give an introductive notes about FET amplifier ?  The small signal models for the common source FET can be used for analyzing the three basic FET amplifier configurations: (

State the drawbacks of in band and out band voice signalling, a. Enlist the...

a. Enlist the benefits and drawbacks of in band and out band voice signalling? b. Describe Channel Associated mode, Channel Non-Associated mode and QuasiAssociated mode of commo

Gto - gate turn off, GTO ( Gate Turn Off) GTO stands for gate  turn o...

GTO ( Gate Turn Off) GTO stands for gate  turn off  thyristor . it is four layer  PNPN  device. It can be  triggered into conduction like a conventional thyristor  by a pulse

Commutation in dc machines, Currents induced in armature conductors of a d....

Currents induced in armature conductors of a d.c. generator are alternating. To make their flow unidirectional in the external circuit, we need a commutator. Moreover, these curren

Switching, With neat diagrams explain the configuration of a step-by-step s...

With neat diagrams explain the configuration of a step-by-step switching system

Biasing the bjt, Q. Biasing the BJT? A simple method of biasing the BJT...

Q. Biasing the BJT? A simple method of biasing the BJT is shown in Figure. While no general biasing procedure that will work in all cases can be outlined, a reasonable approach

Project, Design a DC motor control system to run the 48V DC motor at 40rpm ...

Design a DC motor control system to run the 48V DC motor at 40rpm up to max load of the motor. You are responsible for designing the control of a 24V supply along with the speed s

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