Jfet common source amplifier, Electrical Engineering

Assignment Help:

Q. JFET Common Source Amplifier?

The common source configuration for a FET is similar to the common emitter bipolar transistor configuration, and is shown in figure. The common source amplifier can provide both a voltage and current gain. Since the input resistance looking into the gate is extremely large the current gain available from the FET amplifier can be quite large, but the voltage gain is generally inferior to that available from a bipolar device. Thus FET amplifiers are most useful with high output-impedance signal sources where a large current gain is the primary requirement. The source by-pass capacitor provides a low impedance path to ground for high frequency components of and hence AC signals will not cause a swing in the bias voltage.

Since the FET gate current is small we can make the approximations is = io and vs = - vas the source is positive with respect to the gate for reverse-bias. Since at low frequencies we can ignore the capacitor the source voltage is given by

1655_JFET Common Source Amplifier.png

Using the transconductance equation we can write

2205_JFET Common Source Amplifier.png


Related Discussions:- Jfet common source amplifier

Static characteristics of the npn silicon bjt, Consider the common-emitter ...

Consider the common-emitter BJT circuit shown in Figure (a). The static characteristics of the npn silicon BJT are given in Figure (b) along with the load line. Calculate iB for v

Transformer-coupled amplifiers, Q. Transformer-coupled Amplifiers? Tra...

Q. Transformer-coupled Amplifiers? Transformer-coupled Amplifiers: The figure illustrates another type of coupling often used to couple audio frequencies - the untuned transf

Differences between vga and cga graphics adapters, Q.9 What are the main...

Q.9 What are the main differences between VGA and CGA graphics adapters? Ans: Colour Graphics Adapter (CGA), initially also known as Colour/Graphics Adapter or IBM Colo

Find a local s-matrix for each triangle, Figure shows two first-order trian...

Figure shows two first-order triangular finite elements used to solve the Laplace equation for electrostatic potential.  Find a local S-matrix for each triangle, and a global S-mat

Collector-coupled astable multivibrator, what happens when the resistors ha...

what happens when the resistors have different values

compute the cavity , Consider the optical cavity shown below. (...

Consider the optical cavity shown below. (a) Compute the photon lifetime. (b) Compute the cavity Q (assume that the wavelength region of interest is 500nm). (c) Su

Corrosion, I want to know whether the circuits for both methods(linear pola...

I want to know whether the circuits for both methods(linear polarization resistance and electrochemical impedance spectroscopy) are same or not?

Explain multimeter, Explain multimeter A multimeter, or universal instr...

Explain multimeter A multimeter, or universal instrument, may be used to measure voltage, current and resistance.

Advantage of digital technology, Q. Advantage of digital technology? Th...

Q. Advantage of digital technology? The primary advantage of digital technology is the low cost, simplicity, and versatility of the digital building blocks. Because digital sig

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd