Sources of Distortion and Noise
Robert N. Buono · Focal Press eBooks · 2025
This chapter presents the principal sources of distortion and noise in Class-D audio amplifiers. It distinguishes between open-loop noise mechanisms and closed-loop mechanisms and provides a preliminary discussion of the distortion-reducing effects of negative feedback. The equation for THD is presented. Power switching stage distortion is discussed, as is the distortion caused by passive components, including capacitors, resistors, and inductors. The effect of noise on comparator ramp circuitry is discussed, as are the distortion effects of gate driver propagation delays and pulse-amplitude distortion. Finally, a summary of open- and closed-loop distortion mechanisms is listed.