Definition of Class-D amplifier
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.
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Questions people ask
Real questions from the Stack Exchange community – follow a link to read the discussion.
- How can I see if my filterless class-D audio amplifier is clipping or not? · Electronics SE
- Understanding an unusual combination of crossover diodes in a class AB amplifier · Electronics SE
- What class of audio amplifier is this unusual configuration? · Electronics SE
- Understanding a Class D amplifier design · Electronics SE
- When playing sine into class D amplifier, why is Vdd ripple voltage the 2nd harmonic of the sine? · Electronics SE
- Output Filter Components Breaking Class D Amplifier Chip · Electronics SE
Frequently asked questions
What is Class-D amplifier?
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.
Sources & credits
- Wikipedia: Class-D amplifier – CC BY-SA 4.0
- Image by Rohitbd – CC BY-SA 3.0