The Bipolar Power Transistor (BPT), as a switching device for power applications, had a few disadvantages. This led to the development of the power MOSFET (Metal Oxide Semiconductor Field Effect Transistor). The power MOSFET is used in many applications such as SMPS (Switched Mode Power Supplies), computer peripherals, automotive, and motor control. Continuous research and improvement have provided it with ideal characteristics for replacing the BJT (Bipolar Junction Transistor).This application note is a general description of power MOSFETs and a detailed presentation of items from FSC’s data book specifications.