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

What is an oscillator and show the advantages of oscillators, Q. What is an...

Q. What is an oscillator? Discuss the advantages of Oscillators ? An oscillator is a system consisting of active and passive circuit elements to produce a sinusoidal or other r

Pdc, disadvantages of shunt&series clippers

disadvantages of shunt&series clippers

Estimate the length of the wire required to get a resistance, A heater elem...

A heater element is made of nichrome wire having resistivity equal to 100 × 10 -8 ohm-m. The diameter of the wire is 0.4mm. Calculate the length of the wire required to get a resi

Logic Gates, A former employs a servant to look after his form house. He in...

A former employs a servant to look after his form house. He instructs the servant to keep a watch on his goat. So that he does not harm the kitchen garden, when the entrance-door

Example of registers to registers , Example of Registers Example : W...

Example of Registers Example : Write  the instruction to copy  data byte 24H  stored  in register C to register B  Solution : The instruction to copy  data byte  is  a

Switched mode power supply , Switched Mode Power Supply  (SMPS) Switch...

Switched Mode Power Supply  (SMPS) Switching mode power  supply converts an unregulated DC voltage  to a regulated DC  output  voltage . SMPS  stands  for switched mode  power

Salary, electrical designer salary above 6years experience, in singapore

electrical designer salary above 6years experience, in singapore

What is an amplifier, Q. What is an amplifier? What are the various types o...

Q. What is an amplifier? What are the various types of amplifiers? AMPLIFIER: A circuit that increases the amplitude of the given input signal is an amplifier. A small a.c. sig

Explain virtual memory, Explain virtual memory. The term virtual memor...

Explain virtual memory. The term virtual memory considers as to something that appears to be present but in fact it is not. The virtual memory technique permits users to use m

Explain nodal analysis procedure, Nodal analysis procedure: 1.  Verify ...

Nodal analysis procedure: 1.  Verify the number of common nodes and reference node within the network. 2.  Assign current and its direction to every distinct branch of the n

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