An investigation into the parameters affecting total harmonic distortion in low-voltage low-power class-D amplifiers

• Main Authors: Tan, Meng Tong, Chang, Joseph Sylvester, Chua, Hock Chuan, Gwee, Bah Hwee
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Electrical and electronic engineering
• Online Access: https://hdl.handle.net/10356/90577; http://hdl.handle.net/10220/4638
• Institution: Nanyang Technological University

We investigate the influence of two important practical design parameters on total harmonic distortion (THD) for the design of low-voltage (0.9–1.4 V) low-power analog Class-D amplifiers: the linearity of the carrier waveform and the impedance of the output stage. We show that the carrier nonlinearity results in THD and propose a novel mathematical analysis method to model the nonlinearity. We recommend a range of the parameter that describes the carrier nonlinearity and that results in a good compromise to the dynamic range of the pulsewidth modulator of the Class-D amplifier. We show that the impedance of the output stage has little effect on THD. We verify our analyses by means of MATLAB and HSPICE computer simulations, and on the basis of practical measurements.