Switching characteristics, Electrical Engineering

Assignment Help:

Switching Characteristics

Switching  characteristics  of BJT  are shown  in figure. Due  to the presence of internal  capacitances BJT  cannot be  turned  instantly. Initially when base  emitter  voltage  is applied in CE  configuration leakage current  flows.  The collection current  begins  to rise after  some delay  time  and reaches at its  steady state  value. the time  from which  collector  current  starts  rising  to its  steady  state value  known  as rise time. BJT gets turned on in and collector emitter  voltages falls from  its maximum  value  forward voltage drop.

1431_Switching Characteristics.PNG

 

Till the forward  base  current is  maintained the BJT  remains in  on condition. As  the base emitter  voltage  is removed at a time t1 does not change for a  time ( there  its is  storage time in which the charges are removed from the base).  After  this time Ic begins to fall and collector voltage starts rising  for a time tf  ( fall time ) . in  fall time  decreases to leakage current  and voltage  rises  to vcc. Hence the turn off time  of BJT is  t off = ts +  tf. In conduction period of BJT a steady state  current  flows and  forward  voltage  drop  appears across the  collection emitter  junctions.

 


Related Discussions:- Switching characteristics

Find the equivalent components of the network, Q. At the two terminals (A, ...

Q. At the two terminals (A, B) of a one-port network, the voltage and the current are given to be v(t) =200 √2 cos (377t + 60°) V and i(t) = 10√2 cos(377t + 30°) A. (a) Determin

Wcdma, what is that mean and explain

what is that mean and explain

Weighted resistor and the r-2 r ladder d/a converters, Q. What is the basic...

Q. What is the basic difference between the weighted resistor and the R-2 R ladder D/A converters?

Example of binary subtraction of negative number , Example of binary subtra...

Example of binary subtraction of Negative number Case 2.   Negative number is more than  the positive number ( i e, answer  is negative)  Example : Subtract 92 10 ( 101

History of computers , History of Computers To understand the  inventi...

History of Computers To understand the  invention of microprocessor we have  to see the  history  of computer  first. The growth  the computers  is divided in  different  gener

Design three-bit counter using t flip-flops, (a) A universal shift regist...

(a) A universal shift register can shift in both the left-to-right and right-to-left directions, and it has parallel-load capability. Draw a circuit for such a shift register.

Draw and explain colpitts oscillator, Q. Draw and explain Colpitts oscillat...

Q. Draw and explain Colpitts oscillator? Colpitt's oscillator is a superb circuit which is used widely in commercial signal generations of  frequency of 100 Mhz . It consists o

What is use of co-processor in a typical microprocessor, What is use of co-...

What is use of co-processor in a typical microprocessor based system. This is a processor that works in parallel with the major processor. This has its own set of specialized i

Calculate the antenna parameters, For a helical antenna, the half-power bea...

For a helical antenna, the half-power beamwidth and directive gain are given by where C = πD, N = L/S, and S = C tan α,in which α is called the pitch angle, and The

Distinguish between ferromagnetic and paramagnetic materials, Distinguish b...

Distinguish between ferromagnetic and paramagnetic materials, mentioning at least one example of each. Ferromagnetic Materials: These are materials wherein magnetic dipoles i

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