Recognition of Insulated Layer Gate MOSFETs

Insulation layer gate type MOSFET alias MOSFET (hereinafter referred to as MOSFET), which has a cable sheath of silicon dioxide in the middle of the gate voltage and source drain.

MOSFET is also N-channel and P-channel two categories, but each category is divided into enhancement and light depletion type two, thus there are a total of four types: N-channel enhancement, P-channel enhancement, N-channel light depletion, P-channel light depletion type. But where the gate source voltage is zero, the drain current is also zero of the pipe are enhanced tube. However, where the gate source voltage is zero, the drain current is not zero are categorized as light-consuming type tubes.
Enhanced MOSFET principle:

When working in the middle of the gate source does not use the voltage, the middle of the drain source PN junction is in the opposite direction, so there will be no conductive channel, even if the middle of the drain source with a voltage, the conductive trench electricity is closed, it is not possible to have a working current according to. When the middle of the gate source plus positive direction voltage to a certain value, in the middle of the drain source will produce a conductive safety channel, so that the conductive trench just produced by this gate source voltage is called the open voltage VGS, the larger the middle of the gate source voltage, the conductive trench is wider, which in turn makes through the greater the flow of electricity.

Principle of Light Dissipative MOSFET:

In operation, no voltage is used in the middle of the gate source, unlike the enhancement type MOSFET, and a conductive channel exists in the middle of the drain source, so only a positive voltage is added to the middle of the drain source, which results in a drain current flow. Moreover, the gate source in the middle of the positive direction of the voltage, the conductive channel expansion, add the opposite direction of the voltage, the conductive channel shrinks, through the flow of electricity will be smaller, with the enhancement of MOSFET comparison, it can also be in the positive and negative number of a certain number of regions within the conductive channel.

MOSFET efficacy:

First, MOSFETs are used to enlarge. Because the input resistance of MOSFET amplifier is very high, so the filter capacitor can be smaller, without the need to apply electrolytic capacitors.

Second, MOSFET very high input resistance is particularly suitable for the characteristic impedance conversion. Commonly used in multi-level amplifier input stage for characteristic impedance conversion.

MOSFET can be used as adjustable resistor.

Fourth, MOSFET can be convenient as a DC power supply.

V. MOSFET can be used as a switching element.