Title :
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
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;
Conference_Titel :
Computational and Information Sciences (ICCIS), 2013 Fifth International Conference on
Conference_Location :
Shiyang
DOI :
10.1109/ICCIS.2013.332
