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hi
Main differences are,
Bipolar Junction Transistor:
switching speed is low;switching loss is more; conduction loss is less; frequency of switching is less
we can use as amplifier;Current control; conduction due to electron & holes
Junction field Effect Transistor:
it an unipolar; switching speed is high;so loss is less
voltage control;
Metal oxide semiconductor fet:
it nothiug bt fet, most of time v used for switching device in Smps do to power range
A BJT is a bipolar transistor in the sense that there are two types of charge carriers in them. In npn trnsistor the primary carrier in the hole and in pnp the electron. In JFET there is only one type of carrier. In n-channel case the carrier is elctron and in p-channel hole. So JFET is unipolar in that sense.
BJT is a current controlled device as the input current is amplified subjected to the mode of operation. For example in CE mode the input current is base current and output current is emmiter current which is (β+1) times amplified. The drop of this current across the load voltage is the output signal voltage. But a JFET is a voltage controlled device. The chalnnel conductance is determned by the voltage supplied at the gate terminal and depending on this the drain current flows.
MOSFET is one kind of voltage controlled device like JFET where there is metal oxide in between the gate and the channel. Depending on the voltage supplied on the gate terminal a voltahe is 'induced' by electrostatic induction in the isolated channel. The channel therefore behaves as a capacitor where due to the voltage some charges are induced. These charges shrink or extend the effective chanel width. For example in Enhancement Mosfet the channel width effectively increases and in depletion mosfet it decreases. Depending on this the drain to source current increases or decreasesA BJT is a bipolar transistor in the sense that there are two types of charge carriers in them. In npn trnsistor the primary carrier in the hole and in pnp the electron. In JFET there is only one type of carrier. In n-channel case the carrier is elctron and in p-channel hole. So JFET is unipolar in that sense.
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Difference between de-mosfets e-mosfets and jfets?
The basic theory of operation is the same, but the device structure is different. With both a MOSFET and a JFET, a conductive channel is established between two terminals (the drain and the source). The structure of the gate terminal makes the difference between the two. In a MOSFET, the metal gate is separated from the channel by an insulator (the O in MOSFET means Oxide, the insulator). In a JFET the gate is a doped region essentially within the conductive channel.
What is the difference between jfet and mosfet?
1-BJT is bipolar while JFET is unipolar. 2-BJT has low input impedence while JFET has high input impedence. 3-JFET has low power discipation as compared to BJT. 4-JFET has low noise as compared to BJT. 5-BJT is current controlled while JFET is voltage controlled. 6-JFET is mostly used in digital circuits.
What are the differences betweeen e-mosfet and d-mosfet?
An e-mosfet is and "enhancement" mosfet. A d-mosfet is a "depletion" mosfet. These essentially show what mode the mosfet operates in when a voltage is applied to the gate. . An enhancement mode mosfet is normally non-conducting but conducts when the channel is enhanced by applying a voltage to the gate and pulling carriers into the channel. A depletion mode mosfet normally conducts but becomes more and more non-conducting as carriers are depleted or pulled out of the channel by applying a voltage. The polarity of the voltage depends on whether it is an N channel or P channel. P channel uses positively doped silicon while N channel uses negatively doped silicon. N channel fets are used wherever possible because N material conducts better than P material. There are basically two types of fet, the jfet and the mosfet. The jfet uses a single junction to control the channel hence draws some current. Bipolar transistors use two junctions. In the mosfet (Metal Oxide Semiconducting Field Effect Transistor) there is no such junction hence draw so little current for control purposes it can be regarded as zero. The gate is isolated from the channel by a very thin layer of metal oxide (usually chromium dioxide). An enhacement mode mosfet can be turned on by applying a voltage then removing the wire to the gate. The channel will then remain conducting for some time.
How do you keep mosfet from overheating i use only mosfet and control it using variable resistor it works but it gets overheated and brokedown.My battery operated scooter is 24v dc 72 amp.thank you.?
Use a mosfet driver instead of a simple resistor. Using a resistor to control the mosfet is a bad idea anyways because you will have terrible control (mosfets are voltage controlled. Take a look at the response curve for your mosfet). If your mosfet is fully on, its ratings may be too low for continuous operation or the power dissipation is too low for the transition between off an on an that is killing your mosfet.
What is normally-On MOSFET?
Depletion mode MOSFET is normally on device --vlsijp
Difference between de-mosfets e-mosfets and jfets?
The basic theory of operation is the same, but the device structure is different. With both a MOSFET and a JFET, a conductive channel is established between two terminals (the drain and the source). The structure of the gate terminal makes the difference between the two. In a MOSFET, the metal gate is separated from the channel by an insulator (the O in MOSFET means Oxide, the insulator). In a JFET the gate is a doped region essentially within the conductive channel.
A de mosfet differs from a jfet in the sense that it has no?
channel
What is semiconductor triode?
It can be either a Bipolar Junction Transistor (NPN or PNP) or a Field Effect Transistor (N channel JFET, P channel JFET, N channel MOSFET, or P channel MOSFET).
What is the difference between jfet and mosfet?
1-BJT is bipolar while JFET is unipolar. 2-BJT has low input impedence while JFET has high input impedence. 3-JFET has low power discipation as compared to BJT. 4-JFET has low noise as compared to BJT. 5-BJT is current controlled while JFET is voltage controlled. 6-JFET is mostly used in digital circuits.
Why should a JFET be operated with only reverse bias on the gate?
If the gate-channel junction of a JFET was not reverse biased the JFET would just act as a forward biased diode across that junction and the gate would cease to have any control over the channel conductance. For the same reason in a MOSFET the substrate-source/channel/drain junction must remain reverse biased. The MOSFET could not act as a MOSFET.
What are the classifications of FET?
mosfet, JFET ,these are again divded into many typesdepending upon their material they are made of
What is the difference between igfet and mosfet?
Both are the same!
Difference between de mosfet and e mosfet?
The basic difference is between JFET and enhanced MOSFET,although the construction of JFET and depletion MOSFET is different but their most of the characteridtics are same,i.e shockly equation can be applied on both of them,but in JFET we cant give to gate voltage, the +ve value,because it does not works, but in depletion we can give,but some limited +ve value. Now enhanced MOSFET is different,shockly equation cant be applied.The transfer characteristics are purely in +ve Vg region. i.e for E-MOSFET Vg should be > 0,for its proper function.
What is the difference between depletion type and enhancement type MOSFET?
bnder
What is the difference between mosfet and photo diode?
the current in mosfet is controlled by electric field where as in poto diode is controlled by intensity of light
What is the difference between fet and ujt?
The structure of a UJT is quite similar to that of an N-channel JFET. The main difference is that P-type (gate) material surrounds the N-type (channel) material in case of JFET and the gate surface of the JFET is much larger than emitter junction of UJT.
How a transistor behave as amplifier.What actually happen internally?
MOSFET has high input impedance in comparisson with JFET due to the insulation material of silicon dioxide
