A class-D amplifier or switching amplifier is an electronic amplifier where all power devices (usually MOSFETs) are operated as binary switches. They are either fully on or fully off. Ideally, zero time is spent transitioning between those two states. In this way, power loss is significantly reduced and making a D class amplifier anywhere from 75% to 95% efficient To maintain high efficiency, the filter is made with purely reactive components (inductors and capacitors), which store the excess energy until it is needed instead of converting some of it into heat. Some other advantages include Reduction in size and weight, Reduced power waste as heat dissipation and hence smaller (or no) heat sinks and Reduction in cost due to smaller heat sink and compact circuitry.
Metal–Oxide–Semiconductor Field-Effect Transistor is a transistor used for amplifying or switching electronic signals. We use it in billions of them. In our computers, our telephones, game consoles, cars, electrical appliances and in this case, our Amplifiers. They are found in systems where information is processed or stored. A MOSFET is basically an electrical switch that allows the flow of electrical current. An electrical switch has two possible states, ON or OFF. This is where the MOSFET performs its most important role in our D Class amplifiers by allowing or preventing the flow of power and creating an efficient amplifier. The “Pulse Width Modulated” is a design that is significantly simplifies power supplies. It controls the output voltage and current precisely by not only removing the output current sensing loss, but also eliminating all secondary feedback circuitry. The PWM can increase efficiency, is lighter, smaller, can reduce total cost, productivity and system reliability.