Harmonic distortion reduction in multi-level PWM modulators for audio power amplifiers

This paper presents a new methodology to reduce harmonic distortion in multilevel PWM modulators with uniform sampling. The proposed approach generates pulses with widths longer than a predeterminate value. This ensures the needed time for the calculations and helps to reduce audio distortion introduced by the non-zero rise and fall time of the switches. Therefore the methodology allows smaller harmonic distortions than the inherent of uniform sampled PWM signals. Simulation results are presented.