What is transconductance, Electrical Engineering

Assignment Help:

Q. What is transconductance? Explain its significance from the transfer characteristics.

Transconductance is the transistor gain of the JFET; it indicates the amount of control the gate voltage has on the drain current. The transconductance is defined as

    gm = d(ID)/d(VGS)

Using the expression for the ideal drain currents derived, we can write the expressions for the transconductance.

The drain current for n-channel depletion mode device in the non-saturation region region was given by equation for the pinch off current.

The derivation of the equation for the transconductance leads to the relation shown below

    gms = (-2IDSS)(1-VGS/VP)/VP

The transconductance shows the significance of the transfer characteristics of a JFET.

1987_What is transconductance.png

The transfer characteristic of an FET relate the transfer of the input directly with the output. That is the drain current is directly plotted with the gate source voltage. The graph on the left slowly diminishes in its amplitude as it approaches the x axis. In theory the graph touches the x axis and channel pinches off. But in practical sense the graph does not tough the x axis but goes parallel to it with out touching it. For this reason the gm of the JFET is always a constant value. The transconductance of the JFET relates the ease with which the drain current flows at a particular value of the gate source voltage. The measure of transconductance is done in siemens.


Related Discussions:- What is transconductance

Draw the differentiator circuit, Q. Draw the differentiator circuit. Explai...

Q. Draw the differentiator circuit. Explain its principle of operation with necessary waveforms ? A circuit in which the output voltage is directly proportional to the derivati

The resistance of an electrical conductor, The resistance of an electrical ...

The resistance of an electrical conductor depends on 4 factors, these being:   a)  The length of the conductor   b)  The cross-sectional area of the conductor

What do you mean by companding, Q. What do you mean by Companding? In o...

Q. What do you mean by Companding? In order to lower the crest factor of a waveform, so as to produce better performance, a process known as companding is used. It works like a

Speed control of dc series motor - motor control , Speed Control of DC Seri...

Speed Control of DC Series Motor A half  wave  circuit  for the  speed  control of DC  series motor is  shown in figure and corresponding wave from  is shown  in figure  consis

Coupling, advantages and disadvantages of direct and r c coupling

advantages and disadvantages of direct and r c coupling

Calculate the pu voltage and line to line voltage, The one line diagram of ...

The one line diagram of a simple power system is shown below. The data of the system are given in the table below. (a) Draw the impedance diagram of the system and mark all impe

Discuss the disadvantages of an rc coupled amplifier, Q. Discuss the disadv...

Q. Discuss the disadvantages of an RC coupled amplifier? RC coupled amplifiers have a few disadvantages. The resistors use dc power and so the amplifier has low efficiency. The

Compute the theoretical and practical frequency ranges, Q. For an RG-290/U ...

Q. For an RG-290/U aluminum rectangular wave - guide, a = 58.42 cm and b = 29.21 cm. Compute the theoretical and practical frequency ranges of operation for the guide.

Dc machines, commutator in d.c machine acts as... what????

commutator in d.c machine acts as... what????

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