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

Explain the importance of planning in an organisation, Question 1: Plan...

Question 1: Planning is one of the primary functions of management. (a) Explain the importance of planning in an organisation. (b) How can managers develop an effective a

Define johnson counter to convert serial data, Define johnson counter to Co...

Define johnson counter to Convert Serial Data to Parallel Data? A microprocessor-based or computer system commonly requires incoming data to be in parallel format. But often t

Microcontroller - introduction to microprocessors , Microcontroller Mic...

Microcontroller Microcontroller  is also known  as computer  on a chip  this  includes basic  features of microprocessor (ALU Registers  and control circuits ) with  1 k to 2k

Determine the memory access time, Question: (a) Explain the types of ha...

Question: (a) Explain the types of hazards in a 5 stage pipeline. (b) Describe the three RAW dependencies in the following instructions. i: R7←R12+R15 i + 1: R8←R7-R1

Schrodinger’s wave equation, Discuss the degeneracy of energy of energy sta...

Discuss the degeneracy of energy of energy states. Solve the Schrodinger’s equation for a free particle in three dimensional boxes and find Eigen values and Eigen function of free

Dc machines, singly excited magnetic systems

singly excited magnetic systems

Describe watch dog timer and reaction timer, a. Given a timer with a termin...

a. Given a timer with a terminal count and a clock frequency of 10 MHz measure the following: (i) Range & Resolution (ii) Terminal count values needed to measure 3ms interval

Phasor diagram, The aim of this question is to help you become familiar wit...

The aim of this question is to help you become familiar with phasor diagrams, and in particular to see how the diagram changes when one of the system parameters (in this case resis

Zener breakdown, Zener breakdown: Zener Breakdown takes place in very ...

Zener breakdown: Zener Breakdown takes place in very thin junction i.e. when both sides of junction layer is narrow. When a small reverse bias voltage is applied a Very strong

Static characteristics of the npn silicon bjt, Consider the common-emitter ...

Consider the common-emitter BJT circuit shown in Figure (a). The static characteristics of the npn silicon BJT are given in Figure (b) along with the load line. Calculate iB for v

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