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mainly i will tell ttwo advantages:-
1)in FET "thermal runaway" never occurs but in bjt it occurs easily...thermal runaway means overheating and damage of fet due to different biasing voltages..
2) since FET is a unipolar device so only one carrier type is required here ,but bjt is a bipolar device ..
3) FET is smaller in size than BJT of same rating. i mean to say that at the place of 10 bjts we can use 90 FETs ..so area cosumption is less
Wiki User
∙ 13y ago
Wiki User
∙ 11y agoFollowing are the Advantages of JFET over BJT:
1. Operation of JFET depends upon the flow of majority carriers only i.e. electrons in n-type and holes in p-type semiconductor. Because of this JFET is said to be Unipolar device. Unlike this BJT depends on the follow of both the types of carriers and is a bipolar device.
2. Normally JFETs are extremely immune to any type of radiations which is not so for BJTs.
3. JFET have a high value of input resistance (normally of the order of Meg-ohms), this provides a good isolation between the input and output ts
4. Circuits based on JFET are supposed to be less noisy in their functionality as compared to BJT.
5. JFET exhibits no offset voltage at zero drain current and hence functions as an excellent chopper.
6. In comparison to BJTs JFETs are highly Thermally Stable.
Wiki User
∙ 11y agoFET is more temperature stable than BJT, and FET has low gain-bandwidth product compared with BJT
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What are the three element of a transistor?
For a BJT transistor the three basic elements are collector, base and emitter. For a FET transistor are drain, gate and source which are analogous for the BJT parts mentioned before.
Why there is no thermal runaway in fet?
in FET the conduction is due to the majority carriers. here the minority carrier conduction doesn't takes place as in BJT. hence the current flow depends only on the majority carriers . hence ther is no thermal runaway in FET.
What are the advantages and disadvantages of JFET over BJT?
An advantage of JFET is stable high current operation. A disadvantage of JFET is low capacitance. An advantage of BJT is constant voltage operation. A disadvantage of BJT is low thermal conductance.
Switching speed is high for mosfet or bjt?
generally bjt is faster than fets...because of many intrinsic junction capacitances between ...source and drain and bulk and gate,,,.. but now a days due to advancement in scaling fet is reduced in size sooo much that it became faster than bjt... mosfet is faster because of scaling. small channel length. even though it is slower but distance to be travelled is less
Why FET is called as a unipolar transistor?
The FET is a semiconductor device with the output current controlled by an electric field. Since the current is carried predominantly by one type of carriers, the FET is known as a unipolar transistor.
Why fet is preferred over the bjt?
Disadvantage:Easy to damage when compared to BJT
Why FET produces less noise than BJT?
because the fet is made out of carbon metal oxide and the bjt is made out of silicon or germanium
How biasing of FET differs from biasing of BJT?
in BJT forwardbiasing & reverse biasing are carried out but in FET voltage divider biasing &self biasing are carried out.
What is the difference between jfet and bjt?
FET's (field effect transistors) are unipolar devices because unlike BJT's that use both electron and hole current, they operate only with one type of charge carrier. BJT is a current-controlled device; that is the base current controls the amount of collector current. FET is a voltage-controlled device, where voltave between two of the terminals (gate and source) controls the current through the device. BJT's have a low input impedance ( ~1k -3k ohms), while FET's have a very high input impedance (~10^11 ohms). Consequently FET's have a lower power consumption. BJT's produce more noise than FET's . FET's have a slower switching speed . BJT's are subject to thermal runway while FET's are immune to this problem. BJT's have a higher cutoff frequencey and a higher maximum current then FET's. FET's are easy to fabricate in large scale and have higher element density the BJT's.
What applications would prefer the bipolar junction transistors over the field effect transistor?
bjt is bipolar device whr fet is unipolar....fet is input resistance thts y fet gain is less compared to bjt..... The applications that will prefer bipolar junction transistors to field effect transistors are applications that require fast switching.
What is the main advantage of an fet transistor over a bjt transistor?
BJT & FET parameters are temperature dependent. In BJT the collector junction resistance decreasing ( collector current increasing) with temperature raise.Due to the highe temperature & current transistor will damage quickly. In FET drain resistance increasing (drain current decreasing ) with increasing temperature.Due to this property it will not damage easily. We can say from the above two statements FET is more temperature stable.FET can use in highe temperature applications.
What is bjt and jfet?
BJT is Bipolar junction transistor FET is Field effect Transistor It is a current controlled device It is voltage controlled device
Why bjt is not used of fet in building logic circuit?
land pe char hai
What is the difference between BJT and NPN transister?
Mainly there are two types of transistors. They are BJT (Bipolar Junction Transistors) and FET(Field Effect Transisters). In BJT, there are two types called PNP and NPN. Actually NPN means a BJT transister.
What are the classification of amplifiers according to transistor configuration?
common emitter using fixed bias
What are the three element of a transistor?
For a BJT transistor the three basic elements are collector, base and emitter. For a FET transistor are drain, gate and source which are analogous for the BJT parts mentioned before.
What are the three element of transistor?
For a BJT transistor the three basic elements are collector, base and emitter. For a FET transistor are drain, gate and source which are analogous for the BJT parts mentioned before.
