A Sixth-Order PWM Modulator for Digital Input Class-D Audio Amplifiers

Author

Shumeng Luo ; Dongmei Li

Author_Institution

Tsinghua Nat. Lab. for Inf. Sci. & Technol., Tsinghua Univ., Beijing, China

fYear

2013

fDate

21-23 June 2013

Firstpage

1253

Lastpage

1256

Abstract

A digital Class-D audio amplifier is presented in this paper. This amplifier uses a sixth-order PWM modulator to generate the driver signal of the output stage of the amplifier. The transformation of pulse-amplitude-modulation (PAM) signal to pulse-width-modulation (PWM) signal is moved into the closed sigma-delta modulator loop that the noise and distortion generated during the transformation of PAM signal to PWM signal is suppressed by the high gain of the forward loop of the sigma-delta modulator. Therefore, at the output of the digital modulator, a very clean PWM signal is generated to drive the power stage of the class-D amplifier. This class-D amplifier achieves 110dB dynamic range (DR), 100dB signal to noise rate (SNR) and 0.005% total harmonic distortion plus noise (THD+N).

Keywords

audio-frequency amplifiers; harmonic distortion; pulse amplitude modulation; pulse width modulation; sigma-delta modulation; PAM; THD+N; digital input class-D audio amplifiers; digital modulator; dynamic range; pulse amplitude modulation; pulse width modulation; sigma-delta modulator loop; signal to noise rate; sixth-order PWM modulator; total harmonic distortion plus noise; Clocks; Frequency modulation; Noise; Pulse width modulation; Semiconductor device measurement; Sigma-delta modulation; Class-D; PWM; sigma-delta;

fLanguage

English

Publisher

ieee

Conference_Titel

Computational and Information Sciences (ICCIS), 2013 Fifth International Conference on

Conference_Location

Shiyang

Type

conf

DOI

10.1109/ICCIS.2013.332

Filename

6643249