Mechanical structure of depletion type mosfet, Electrical Engineering

Mechanical Structure of Depletion Type MOSFET

The mechanical structure of this type of device is displayed in figure. In an IC, we would locate two n-type regions side by side in a p-type area and then place the gate in between the n-type regions. Though, the important region still contains the two n-type regions and the p-type area in between them.

Without applied bias, we have what amounts to an npn transistor without base connection. The two n-type regions are electrically separate and isolated from each other. Although with a voltage applied in between the two n-type regions, there is no channel present and no current flow.

563_Mechanical Structure of Depletion Type MOSFET.png

Whereas we still apply the usual positive voltage to the drain with respect to the source, this time we will as well apply a positive voltage to the gate region. This comprises the effect of attracting free electrons in the direction to the gate. The larger the positive gate voltage, the wider its electric field and the much more free electrons it will attract.

You may not think this would have any influence on the p-type region, in which the majority current carriers are holes. Though, there are some free electrons here also. Additionally, the source junction is forward biased, thus the positive gate voltage can attract electrons across this junction towards the gate.

The net result is that the electrons attracted in the direction to the gate actually improve a channel within the p-type region, as displayed in figure. This is a channel that is made up of free electrons, and actually bridges the gap in between source and drain. Now we have a channel that can conduct current from source to drain by the device.

Posted Date: 1/11/2013 1:41:29 AM | Location : United States







Related Discussions:- Mechanical structure of depletion type mosfet, Assignment Help, Ask Question on Mechanical structure of depletion type mosfet, Get Answer, Expert's Help, Mechanical structure of depletion type mosfet Discussions

Write discussion on Mechanical structure of depletion type mosfet
Your posts are moderated
Related Questions
Hello may i know if it is possible for me to teach online on electrical maters?

The Lennox to Bowmanville 500 kV circuit, spanning a distance of about 180 km, has series (inductive) impedance j 0.0224 pu and shunt (capacitive) admittance j 2.34 pu, quoted on b

States Kirchoff's Voltage Law Kirchoff's Voltage Law (KVL) describes in any closed loop in a network, the algebraic sum Figure of the voltage drops (i.e. products of current

Q. The response y(t) of a linear system to an excitation x(t) = e -2t u(t) is y(t) = (t + 2)e -t u(t). Find the transfer function.

a) In the United States, the Federal Communications Commission (FCC) is charged with the regulation of radio and wire communication (FCC part 15). It basically sets limits on the

Q. Mention some characteristics of transistors? · When a NPN transistor is working, there is always a constant 0.6 volt drop between the base and emitter, i.e., the base is alw

1. Frequency Modulation theory and its explanation 2. FM transmitter schematic, tests results and measurements 3. Amplifier and Oscillator circuit explanation and calculation

Using the LM741operational amplifier build a current amplifier with the voltage gain of  |A V | = 300 v/v ± = 20% . Measure all necessary parameters of the amplifier (as per delive

Explain the Parallel In - Parallel Out Shift Registers? For "parallel in - parallel out" shift registers all data bits show on the parallel outputs immediately following the si

What do you maent by Debugger? Debugger: This is a program that allows user to debug and test programs. All computers with microprocessor kits give debugging facility. To not