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

DC Generator, What is Commutator? Explain in brief about the Commutator act...

What is Commutator? Explain in brief about the Commutator action in dc generator.

Impact of diversity, Both GSM and DECT use GMSK, but with different Gaussia...

Both GSM and DECT use GMSK, but with different Gaussian filters (BGT = 0.3 in GSM, BGT = 0.5 in DECT). What are the advantages of having a larger bandwidth time product? Why is the

Comparison between motorola processors and intel processors, Differentiate ...

Differentiate between Motorola processors and INTEL processors. Comparison between Motorola processors and INTEL processors: AMD/Intel processors are actually about similar t

Bi directional buffer 74ls245 , Bi Directional Buffer 74LS245 This types...

Bi Directional Buffer 74LS245 This types  of bi directional  buffer is required for data  bus as it has  to function as bi directional bus. The logic  diagram  of such  buffer i

Determine the voltages, Question: a) For the circuit shown in figure ...

Question: a) For the circuit shown in figure (i) Determine the voltages across R1 and R2 and (ii) Determine the current which flows across R1 and R2. Both D1 and D2 a

Define shunt capacitors and reactors, Define Shunt Capacitors and Reactors ...

Define Shunt Capacitors and Reactors Shunt capacitors absorb leading VArs (i.e. they are used to supply lagging VArs) whereas reactors are used to absorbs lagging VArs. Capacit

Power system, a rectangular surge of 2us duration and magnitude of 100Kv tr...

a rectangular surge of 2us duration and magnitude of 100Kv travels along a line of surge impedance 500 ohms. The latter is connected to another line of equal impedance through an i

Explain series capacitors, Explain Series capacitors These are connecte...

Explain Series capacitors These are connected in series with the line conductors and are used to reduce the inductive reactance of long transmission lines and hence the voltage

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