Field effect transistor (is an electronic component that controls the current through the electric field effect. It depends on the electric field to control the shape of the conductive channel, and therefore can control the conductivity of the channel of a certain type of carrier in the semiconductor material. Then the characteristics of the field effect transistor What are we going to? Let's find out.
Field effect transistor features:
1, FET is a voltage control device, which controls ID through VGS;
2. The input current of the FET is very small, so its input resistance is very large.
3, it is the use of majority carrier conduction, so its temperature stability is better;
4. The voltage amplification factor of its amplifier circuit is smaller than the voltage amplification factor of the triode amplifier circuit;
5. The FET has strong anti-radiation ability;
6. Noise is low because there is no shot noise caused by the spread of a small number of random movements.
What is the role of field effect transistors?
1. Field effect transistors can be used for amplification. Since the input impedance of the FET amplifier is high, the coupling capacitor can have a small capacitance and it is not necessary to use an electrolytic capacitor.
2. The high input impedance of the FET is very suitable for impedance conversion. The input stage commonly used for multi-stage amplifiers performs impedance conversion.
3. FETs can be used as variable resistors.
4. The FET can be conveniently used as a constant current source.
5. Field effect transistors can be used as electronic switches.