What are the uses of mosfet, Electrical Engineering

Assignment Help:

Q. What are the uses of MOSFET?

The most common use of MOSFET transistors today is the CMOS (complementary metallic oxide semiconductor) integrated circuit which is the basis for most digital electronic devices. These use a totem-pole arrangement where one transistor (either the pull-up or the pull-down) is on while the other is off. Hence, there is no DC drain, except during the transition from one state to the other, which is very short. As mentioned, the gates are capacitive, and the charging and discharging of the gates each time a transistor switches states is the primary cause of power drain.

The C in CMOS stands for 'complementary'. The pull-up is a P-channel device (using holes for the mobile charge carriers) and the pull-down is N-channel (electron carriers). This allows busing of the control terminals, but limits the speed of the circuit to that of the slower P device (in silicon devices). The bipolar solutions to push-pull include 'cascode' using a current source for the load. Circuits that utilize both unipolar and bipolar transistors are called BiFet. A recent development is called 'vertical P'. Formerly, BiFet chip users had to settle for relatively poor (horizontal) P-type FET devices. This is no longer the case and allows for quieter and faster analog circuits.

FETs can switch signals of either polarity, if their amplitude is significantly less than the gate swing, as the devices (especially the parasitic diode-free DFET) are basically symmetrical. This means that FETs are the most suitable type for analog multiplexing. With this concept, one can construct a solid-state mixing board, for example.

The power MOSFET has a 'parasitic diode' (back-biased) normally shunting the conduction channel that has half the current capacity of the conduction channel. Sometimes this is useful in driving dual-coil magnetic circuits (for voltage spike protection), but in other cases it causes problems.

The high impedance of the FET gate makes it rather vulnerable to electrostatic damage; though this is not usually a problem after the device has been installed. A more recent device for power control is the insulated-gate bipolar transistor, or IGBT. This has a control structure akin to a MOSFET coupled with a bipolar-like main conduction channel. These have become quite popular.


Related Discussions:- What are the uses of mosfet

Show the r’s complement, Q. Show the r’s Complement? Step1- get the (r-...

Q. Show the r’s Complement? Step1- get the (r-1)'s complement Step 2- add 1 to the result ex.            935 10                                     9 9 9

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

Define and explain numerical aperture, Define and explain Numerical apertur...

Define and explain Numerical aperture? Figure shown below shows an incident ray to the fibre, The light bends at two interfaces, one at the air- core interface and the

Transistor, what is bias compensation

what is bias compensation

Find the line current delivered by the source, Q. Balanced wye-connected lo...

Q. Balanced wye-connected loads drawing 10 kW at 0.8 power factor lagging and 15 kW at 0.9 power factor leading are connected in parallel and supplied by a 60-Hz, 300-V, three-phas

Circuit symbols for mosfet, Circuit Symbols for MOSFET A range of symb...

Circuit Symbols for MOSFET A range of symbols are employed for the MOSFET. The basic design is usually a line for the channel along with the source and drain leaving it at rig

What are the various tones used in stronger telephony, Q. What are the vari...

Q. What are the various tones used in stronger telephony? When called party line is obtained, exchange control equipment transmits out the ringing current to telephone set of t

Dc generater, define all the symbols with their unit

define all the symbols with their unit

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