Class-D amplifier

Common card · No. 239732

A class-D amplifier, or switching amplifier, is an electronic amplifier in which the amplifying devices (transistors, usually MOSFETs) operate as electronic switches, and not as linear gain devices as in other amplifier classes. Class-D amplifiers operate by rapidly switching back and forth between the power supply rails, using pulse-width modulation, pulse-density modulation, or related techniques to produce a pulse train output. Little energy is dissipated in the amplifying transistors because they are always either fully on or fully off, so efficiency can exceed 90%. A low-pass filter is typically used to attenuate the pulse train output high-frequency content to reduce quiescent current and electromagnetic interference, resulting in the final analog output current and voltage to be sent to the speaker.

Read on Wikipedia · Image Rohitbd, CC BY-SA 3.0