Output characteristics , Electrical Engineering

Output Characteristics

The output  or drain  characteristic of N - Channel  power MOSFET. When gate  is made positive with respect to the source an N type  channel  is formed  close to the gate. In  this case N +type  substrate  and the N source terminal. When  Vgs  is zero  or negative no channel exists  and the drain current is  zero with the increase in gate  voltage the channel resistance is reduced and therefore the drain current ID  increases thus the  drain current ID remains fairly  constant  over a wide range of Vps levels. Drain terminal  beings  at the bottom  of the power  MOSFET. It can have a considerable large area for any given  of the  device which  allows  more  power  dissipation.

1343_Output Characteristics.PNG

                                                   Figure  output  characteristics of N channel power MOSFET

When Vas is zero  or negative and the  drain  is positive  with  respect to  source the  junctions  between the P layer  and the N layer is  reverse biased. The  depletion region  at eh junction penetrates deep  into the N layer  and thus  punch through  from  drain to source is avoided.

The  lower  most  curve is for  VGS ( Th.)  when VGS< VGS(Th.)  drain  current  is almost  zero when VGS> VGS(Th.)  the device is  ON. This  device has  three  regions ohmic region  active region and breakdown  region. The  rising part of  curve (from  BDS= 0 to VDS=  few volts)  is the ohmic region. The  device behaves as a resistor  when  operated in this region. The  drain  current is almost constant when the device operates in the active region.ehn BDS excess the rated value avalanche breakdown occur and the device is in the breakdown  region. Vgs  can be positive and negative. The  characteristics of P channel  power MOSFET  are similar to those of N channel  MOSFET except that the current  directions and voltage  polarities are reversed.

 

Posted Date: 4/2/2013 5:10:14 AM | Location : United States







Related Discussions:- Output characteristics , Assignment Help, Ask Question on Output characteristics , Get Answer, Expert's Help, Output characteristics Discussions

Write discussion on Output characteristics
Your posts are moderated
Related Questions
Q. An integrator with positive voltage on a noninverting input is shown in Figure. Sketch v o for 60 ms after S has been opened.

Q. Define Resistance Strain Gauge? Mechanical and civil engineers routinely employ the dependence of resistance on the physical dimensions of a conductor to measure strain. A s

List few applications of microprocessor-based system. It is used: i. For measurements, display and control of current, voltage, temperature, pressure, etc. ii. For traff

Q. The radiation pattern of a half-wave dipole antenna is given by (a) Sketch the radiation pattern in the principal plane of xz containing angle θ. (b) Determine the beam wi

A moving coil galvanometer consists of a coil  in a uniform magnetic field B o, suspended fro a fibre of torque constant C, current I produces a deflection O=nAB o i/c where n is

A photodiode is made to detect light quickly a solar cell is made to collect energy from light. They are both typically silicon diodes, but modified to meet their dissimilar requir

Speed Control of DC Shunt Motor V dc   the output of rectifying circuit which is  applied to the motor field  as shown  in figure  for armature voltage V dc   is controlled by

Regenerative Braking Control In this  methods  motor  behaves like a  generator  and the kinetic energy of the  motor  and connected load is  returned to the supply. If means

A Platinum resistance temperature sensor has a resistance of 120 ohm at 0°C and forms one arm of a Wheatstone bridge. At this temperature the bridge is balanced with each of the ot

State the Advantages of expert systems -  Never "forgets" to ask a question in determining the logic -  provides consistent answers - Less skilled work force needed, ther