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Although a small part of the transistor current is due to the flow of majority carriers, most of the transistor current is due to the flow of minority carriers and so BJTs are classified as 'minority-carrier' devices.
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What are the example current controlled device?
Bipolar junction transistor(BJT)
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.
Why bjt is called current controlled current device?
Because the operation of the transistor is determined by the current at the base. the principle equations of BJT operation are: Ic = h*Ib ,and Ie=Ib+Ic thus device operation is controlled by the input current.
Advantages of fet over bjt?
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
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.
Difference between bjt and ujt?
UJT is the voltage controlled device.in which only one mejority carriers are responsible for current flowing. UJT is one junction transistor and it is three terminal emitter and two base. BJT is the current controlled device. in which both mejority and minority carrier are responsiblefor current flowing. this type of transistor consists of two junction and three terminal these are : emitter , base , collector.
What are the example current controlled device?
Bipolar junction transistor(BJT)
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
How works bjt transistor as a sram device?
Define BJTSRAM?
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.
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 current controllable devices?
BJT is a example for current controll device. And JFET is a voltage controlled device.
How do you make ujt with npn and pnp transistors?
You dont. A UJT is a much simple device than either of those BJT's Maybe you want to make a multivibrator out of BJT's?
Why bjt is called current controlled current device?
Because the operation of the transistor is determined by the current at the base. the principle equations of BJT operation are: Ic = h*Ib ,and Ie=Ib+Ic thus device operation is controlled by the input current.
What can transistors be?
either field effect (JFET, MOSFET) or junction (BJT) or point contact (usually considered obsolete)either small signal or high powereither electron majority carrier (N-channel FET, NPN BJT) or hole majority carrier (P-channel FET, PNP BJT)either linear (used in amplifier and oscillator circuits) or switching (used in digital logic circuits)etc.
Transistors can be either what or what?
either field effect (JFET, MOSFET) or junction (BJT) or point contact (usually considered obsolete)either small signal or high powereither electron majority carrier (N-channel FET, NPN BJT) or hole majority carrier (P-channel FET, PNP BJT)either linear (used in amplifier and oscillator circuits) or switching (used in digital logic circuits)etc.
Why FET called current controlled device?
BJT is a current controlled device because its output current is dependent upon the current in the base while for FET it is controlled by the voltage at the gate terminal of the transistor. BJT is a current controlled device because its base current is not zero while for a FET the gate current is zero
