How Does a Power MOSFET Work?

There are several types of Metal Oxide Semiconductor Field-Effect Transistors, also known as MOSFETs. MOSFETs are devices used as transistors in analog or digital circuits. They can either switch or amplify electronic signals. Power MOSFETs are specifically designed to manage large amounts of power and have high impedance levels.

Power MOSFETs were first developed in the late 1970's, first being created by International Rectifier in 1978. While Power MOSFETs perform the same functions as Bi-polar transistors, Power MOSFETs are voltage controlled, while Bi-polar transistors are current controlled.

Power MOSFETs are efficient at lower voltages, and are the most common low-voltage switches. They can be found in most power converters, power supplies and low-voltage controllers. Power MOSFETs utilize a vertical structure, which allows the transistor to sustain high current with high-blocking voltage.

MOSFETs operate under the application of power from a power source. When positive voltage comes from a power source, electrons are attracted to the positive voltage. If the voltage is above a certain level of voltage, enough electrons will be attracted and will accumulate to form a conducting channel across the body of the MOSFET. This channel allows electrons to flow in either direction.