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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.
Wiki User
∙ 11y ago
Wiki User
∙ 9y agoBJT stands for Bipolar Junction Transistor. The advantages include the fact that it runs in a medium to high range of voltage, and that the current density is high. As far as disadvantages go, it doesn't have a very fast switching time, and the base control is quite complex.
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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
What does gm0 represent in a BJT amplifier circuit?
gm0 is not used in BJT amplifier circuits; it is used in JFET circuits. It is the transconductance at zero gate bias. Since the transconductance varies as the bias is varied, this gives a benchmark level at a given defined point, and other transconductances can be calculated from it as a function of the amount of negative bias on the gate. If it were linear it would be the same everywhere, but it is not.
What are the example current controlled device?
Bipolar junction transistor(BJT)
How many terminals does BJT have?
Three.
What are the characteristics of bipolar junction transistor?
A Bipolar Junction Transistor(a.k.a. a BJT or BipolarTransistor) is an activesemiconductor deviceformed by twoP-N junctionswhose function is amplification of an electriccurrent.
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
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
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 current controllable devices?
BJT is a example for current controll device. And JFET is a voltage controlled device.
Why fet is preferred over the bjt?
Disadvantage:Easy to damage when compared to BJT
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.
What are the advantages and disadvantages of MOSFET?
Advantages:- 1- mosfet are small compare to bjt's so it fabricated easily and space saving scheme on the ic's 2- mosfet's input impedance are very high so they do not load the circuits. loading effect doesn't arise. 3- operating frequency is very high so may be used at higher frequencies. 4- used in digital circuits for it's reliability. 5- effect of noise is less than bjt. so high signal to noise ratio. 6-mosfets are unipolar devices so reverse saturation current doesn't exist. 7- it consume less D.C power rather than BJT. Disadvantages:- handling is not easy- Mosfet is very sensitive to electrostatic charge so it may be destroy when you touch the pins of a mosfet devices by hand. trans conductance is low than BJT.
How a transistor use as a switch?
A transistor (bipolar junction transistor BJT) will only conduct in ONE DIRECTION. And the voltage drop is not Ohmic - it is *NOT* strictly related to current flow. If you're referring to a Field-Effect Transitor (JFET, IGFET, MOSFET, etc), then the device may be able to be used in a bidirectional circuit. But the question stated "transistor", which is understood to be a BJT.
How is a transistor used as a switch?
A transistor (bipolar junction transistor BJT) will only conduct in ONE DIRECTION. And the voltage drop is not Ohmic - it is *NOT* strictly related to current flow. If you're referring to a Field-Effect Transitor (JFET, IGFET, MOSFET, etc), then the device may be able to be used in a bidirectional circuit. But the question stated "transistor", which is understood to be a BJT.
What does gm0 represent in a BJT amplifier circuit?
gm0 is not used in BJT amplifier circuits; it is used in JFET circuits. It is the transconductance at zero gate bias. Since the transconductance varies as the bias is varied, this gives a benchmark level at a given defined point, and other transconductances can be calculated from it as a function of the amount of negative bias on the gate. If it were linear it would be the same everywhere, but it is not.
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.
