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Q: Why source is more negative than gate in JFET?
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Why should a JFET be operated with only reverse bias on the gate source?

What is the venin and norton equivalent circuit comment?Read more: What_is_the_venin_and_norton_equivalent_circuit_comment


Why the n-jfet is operated with the negative voltage not the positive voltage?

In a JFET the only insulation between the gate and the channel is a reverse biased diode junction, if this junction becomes forward biased then the gate and channel are effectively shorted and the device no longer acts as a transistor (it will act as a forward biased diode instead). In the n-channel JFET, the gate is the P-side of this diode and the channel is the N-side of this diode. To keep this diode reverse biased (and the device operating as a transistor) therefor the gate MUST always be maintained at a voltage more negative than the most negative section of the channel.


What happens if a negative voltage is applied to the gate of the n and p channel MOSFET?

It depends on: 1. technology, whether it's a JFET, enhancement-mode IGFET/MOSFET or depletion-mode IGFET/MOSFET, and 2. polarity, whether it's an N type or P type. More info needed for this one.


Difference between UJT and FET?

the differences between UJT and FET are :- 1. structural :- a. there is only one p-channel in the UJT where as two in JFET b. the p-channel of UJT is more highly doped when compared to p-channel in JFET 2. functional :- UJT always works in forward biased condition (gate is forward biased) where as JFET always work in rverse bias condition (gate is reverse biased)


What are the applications of jfet transistor?

The Junction Field Effect Transistor (JFET)exhibits characteristics which often make it more suited to a particular application than the bipolar transistor. Some of these applications are: - High Input Impedance Amplifier - Low-Noise Amplifier - Differential Amplifier - Constant Current Source - Analogue Switch or Gate - Voltage Controlled Resistor


What are depletion and enhancement mosfet?

A depletion MOSFET is a MOSFET that is normally on. It outputs maximum current when the gate-source voltage is 0V. As the gate-source voltage increases, the drain-source channel becomes more resistive and the current decreases. An enhancement MOSFET has the opposite behavior. It is normally off. It outputs no current when the gate-source voltage is 0V. As the gate-source voltage increases, the drain-source channel becomes less resistive and the current increases.


When was Lions Gate Bridge created?

For the source and more detailed information concerning your request, click on the related links section (Wikipedia) indicated directly below this answer section.


Why is n channel JFET preferred to p channel JFET?

The mobility of N type charge current carriers is more than two times greater than the mobility of P type charge carriers . Resulting in faster transistor operating speed .


Why triac is called as bidirectional controlled device?

The TRIAC is called a bidirectional controlled device because it operates in two quadrants. It will conduct when MT2 is more positive than MT1 while the gate is more positive than MT1, and will also conduct when MT2 is more negative than MT1 while the gate is more negative than MT1.While not exactly the same thing, an SCR can appear to operate like a TRIAC if the SCR is placed at the center of a bridge rectifier. (Its not exactly the same thing because of the forward drop of the bridge diodes and because the gate voltage is different in this mode of operation.)


Difference between jfet and mosfet?

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.


Why MOSFET breakdown during normal handling?

Human body have electrostaticelectricity and MOSFET are made with Field Effect Transistor, a kind of transistor very sensitive to electricity including electrostatic. Specifically, MOSFETs have a very thin gate oxide layer, which insulates the gate from the source and drain. Exceeding the gate voltage limit can "punch a hole" in the oxide layer, so to speak, causing permanent damage to the device. The gate oxide is much more sensitive to electrostatic discharge than the source/drain junctions.


Why was the field effect transistor invented?

Field-effect transistors were invented by Julius Edgar Lilienfeld in 1925 and by Oskar Heil in 1934, but practical devices were not able to be made until 1952 (the JFET). The MOSFET, which largely superseded the JFET and had a more profound effect on electronic development, was first proposed by Dawon Kahng in 1960.