A metal-oxide-semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET) is a field-effect transistor (FET with an insulated gate) in which the voltage controls the device's conductivity.
It is employed for signal amplification or switching.
Electronic signals can be switched or amplified by using the conductivity's ability to change with the applied voltage.
In both digital and analog circuits, MOSFETs are now even more prevalent than BJTs (bipolar junction transistors).
APPLICATIONS: Designed especially for high voltage, high speed applications, such as off-line switching power supplies, UPS, AC and DC motor controls, relay and solenoid drivers.