How to Use MOSFETs in Switching and Amplifier Circuits

How to Use MOSFETs in Switching and Amplifier Circuits

MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) are fundamental components in modern electronics, prized for their high input impedance, fast switching capabilities, and scalability. Their usage spans from low-power analog circuits to high-power switching converters. This article delves deeply into how to effectively use MOSFETs in switching and amplifier configurations, offering detailed explanations, practical design considerations, and useful FAQs. 1. Introduction to MOSFETs A MOSFET is a type of field-effect transistor that controls the flow of current using an electric field. There are two main types: Enhancement-mode MOSFETs (E-MOSFETs) : Normally off. Require gate voltage to conduct. Depletion-mode MOSFETs (D-MOSFETs) : Normally on. Require negative gate voltage (for n-channel) to turn off. MOSFETs also come in n-channel and p-channel varieties. N-channel devices are generally preferred due to better electron mobility, which gives them lower ON resistance and faster switc…