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 pre-determinate value. This ensures the needed time for the calculations and helps to reduce audio distortion introduced by the nonzero 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.