What are the types of field effect transistor?

There are two types of field-effect transistors, the Junction Field-Effect Transistor (JFET) and the “Metal-Oxide Semiconductor” Field-Effect Transistor (MOSFET), or Insulated-Gate Field-Effect Transistor (IGFET).

What is the main application of a field effect transistor?

Apart from these, FETs are extensively used in Integrated Circuits (ICs) due to their compact size. They are used in mixer circuits of TV and FM receivers due to low intermodulation distortions. Moreover FETs are also used as voltage-variable resistors in OP-AMPS, tone control circuits and JFET voltmeter design.

What is FET and its characteristics?

A FET is a three terminal device, having the characteristics of high input impedance and less noise, the Gate to Source junction of the FET is always reverse biased. In amplifier application, the FET is always used in the region beyond the pinch-off.

How does the gate of a field effect transistor work?

Field Effect Transistor – the basics. In this way, the gate of the FET controls the flow of carriers (electrons or holes) flowing from the source to drain. It does this by controlling the size and shape of the conductive channel. The semiconductor channel where the current flow occurs may be either P-type or N-type.

How is the conductivity of a field effect transistor determined?

Field-effect transistor. Field effect transistors generally display very high input impedance at low frequencies. The conductivity between the drain and source terminals is controlled by an electric field in the device, which is generated by the voltage difference between the source and the gate of the device.

What’s the difference between a JFET and bipolar transistor?

A voltage applied between the source terminal and a GATE terminal (equivalent to the base) is used to control the source – drain current. The main difference between a JFET and a bipolar transistor is that in a JFET no gate current flows, the current through the device is controlled by an electric field, hence “Field effect transistor”.

Why does a JFET junction effect transistor have a high impedance?

As it is only the electric field that controls the current flowing in the channel, the device is said to be voltage operated and it has a high input impedance, usually many megohms. This can be a distinct advantage over the bipolar transistor that is current operated and has a much lower input impedance.