Why fet is a voltage sensitive device, Electrical Engineering

Assignment Help:

Q. Why FET is a voltage sensitive device explain from the drain characteristics?

The JFET consists of a thin layer of n-type material with two ohmic contacts,the source S and the drain D ,along with two rectifying contacts ,called the gates G .If a positive voltage is placed between drain and source,electrons will flow from source to drain .This conducting path between the source and the drain is called a channel.

Consider holding the drain source voltage fixed and varying the gate-source voltage .As the gate-source voltage is made negative ,the gate channel  pn junction is   reverse biased ,increasing the depletion red\gion between the gate and source .This decreases the channel width ,increasing the channel resistance.if the drain-source voltage  VDS is kept constant   ,the current IDS  decreases .when the gate-source voltage  is  made positive,the depletion region decreases until,for large positive gate-source voltages ,the channel opens .then the pn- junction  between gate and channel  becomes  forward biased and current flows from the gate to the source current Summarizing we find that varying the gate voltage varies the channel width ,and hence the channel resistance  .This  inturn  varies the current from drain to source,IDS .We see that it is the gate-source voltage variation which varies IDS ; thus the FET is a voltage sensitive device ,compared with the junction transistor , which is a current sensitive device.


Related Discussions:- Why fet is a voltage sensitive device

Power suppliers, Normal 0 false false false EN-IN X-N...

Normal 0 false false false EN-IN X-NONE X-NONE POWER SUPPLIERS

Mesh analysis, i am battling with mesh, node anaalysis, superposition, node...

i am battling with mesh, node anaalysis, superposition, node thevenin and norton equivalents

Assignment, Hi, I got assignment to design a power electronic system Design...

Hi, I got assignment to design a power electronic system Design the circuit and select the appropriate components for that circuit to fulfil the requirements of the device. Regards

Series-carry synchronous counter with t flip-flops, Q. Consider a series-ca...

Q. Consider a series-carry synchronous counter with T flip-flops shown in Figure in which the AND gates carry forward the transitions of the flip-flops, thereby improving the speed

What is a bode plot and what are i''s uses, Q. (i) What are the different t...

Q. (i) What are the different types of plots for frequency response in an RC coupled amplifier?     (ii) What is a Bode Plot? What are it's uses? The different types of

Explain thevenin''s theorem procedure, Thevenin's theorem procedure:   1. ...

Thevenin's theorem procedure:   1.  Open circuit R L and find Thevenin's voltage (V TH ). 2.  Find Thevenin's resistance (R TH ) when voltage source is short circuit or curren

Classification of feedback control systems by control action, Classificatio...

Classification of Feedback Control Systems by Control Action A more common means of describing industrial and process controllers is by the way in which the error signal E(s) i

What is the purpose of clock signal in an 8086 system, What is the purpose ...

What is the purpose of clock signal in an 8086 system? 8086 needs clock signal with 33%duty cycle from some external operations.8086 processor needs 5 MHZ clock signal

Find the fourier-series expansion of the pulse train, The rectangular pulse...

The rectangular pulse train of Figure (a) consists of pulses of height A and duration D. Such pulse trains are employed for timing purposes and to represent digital information. Fo

Bcd to excess 3 code converter, What are the industrial applications of the...

What are the industrial applications of the project bcd to excess 3 code converter?

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