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Due to high input impedence curret gain is high
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How can transistors act as amplifiers?
The small signal model for the common source FET can be used for analysing the basic FET amplifierconfigurations:(i)common source(CS),(ii)commondrain(CD) or source follower,and(iii)common gate(CG). The CS amplifier which provides good voltage amplification is most frequentlyused.The CD amplifier with high input impedance andnear-unity voltage gain is used as a buffer amplifier and the CG amplifier is used as a high frequencyamplifier.The small signal current-sourcemodel for the FET in CS configuration and the voltage source model can be derived by finding the Thevenin'sequivalent for the output part of amplificationfactor,drain resistance andtransconductance/mutual conductance of the FET.
Does the power amplifier amplifies the power?
the final stage of a power amp is a current amplifier in a bipolar design and a voltage amp in a FET design.
What is the voltage gain of the FET amplifier?
It can be answered in two ways : 1. ratio of output & input voltages [Vout / Vin] i.e Drain voltage(Vds)/Source voltage(Vs). 2. multiplication of trans-conductance & drain resistance .
What is Cut-off voltage in fet?
fet is a voltage controlled device...cut off voltage in fet refers to that voltage of the gate - source junction at which the current flow through channel is zero
Why jfet called as fet?
FET is a field effect transistor, abbreviated to FET. There are two basic types of FET: a junction FET abbreviated to JFET and an insulated gate FET , abbreviated to IGFET. The most common type of IGFET is a metal-oxide silicon FET, Known as a MOSFET. Modern microprocessors may contain tens of millions of MOSFETs.
What are three configurations that can be used with FET devices?
configurations of Common-source (CS), Common-drain (CD) or Source-follower (SF) and the Common-gate (CG) available for most FET devices. These three JFET amplifier configurations correspond to the common-emitter, emitter-follower and the common-base configurations using bipolar transistors.
How can transistors act as amplifiers?
The small signal model for the common source FET can be used for analysing the basic FET amplifierconfigurations:(i)common source(CS),(ii)commondrain(CD) or source follower,and(iii)common gate(CG). The CS amplifier which provides good voltage amplification is most frequentlyused.The CD amplifier with high input impedance andnear-unity voltage gain is used as a buffer amplifier and the CG amplifier is used as a high frequencyamplifier.The small signal current-sourcemodel for the FET in CS configuration and the voltage source model can be derived by finding the Thevenin'sequivalent for the output part of amplificationfactor,drain resistance andtransconductance/mutual conductance of the FET.
What is input impedance of fet amplifier?
Zin=Vds/Id [Vds=drain to source voltage ; Id = drain current]
Why the voltage gain of an FET amplifier is generally less than that obtained using BJT amplifier?
A FET (Field Effect Transistor) is mainly used when the input signal needs to be isolated from the output. A FET has a very high input resistance, so very little current is required from the input. Voltage gain is not the main objective when using a FET.
Does the power amplifier amplifies the power?
the final stage of a power amp is a current amplifier in a bipolar design and a voltage amp in a FET design.
Source to drain in FET is made of which material?
Semiconductor.
What does it mean to source current?
the source current is the current that flows from the power source.
What is Cut-off voltage in fet?
fet is a voltage controlled device...cut off voltage in fet refers to that voltage of the gate - source junction at which the current flow through channel is zero
Fet in cut off voltage?
fet is a voltage controlled device...cut off voltage in fet refers to that voltage of the gate - source junction at which the current flow through channel is zero
What is the voltage gain of the FET amplifier?
It can be answered in two ways : 1. ratio of output & input voltages [Vout / Vin] i.e Drain voltage(Vds)/Source voltage(Vs). 2. multiplication of trans-conductance & drain resistance .
Could you briefly explain the applications of FET?
Due to its *low noise *high input impedence and low output impedence FET is used in numerous applications. *Buffer ampliier *Phase shift oscillator *Integrator *Amplifier
Why the name is FET?
FET stands for Field Effect Transistor. The name FET comes because the gate current of a field effect transistor is zero and current present in the source conductor is due to an electric field produced by the substrate material placed between the gate and the source.
