Class-D Amplifier Power Stage With PWM Feedback Loop

Author

Chun Kit Lam ; Meng Tong Tan ; Cox, S.M. ; Kiat Seng Yeo

Author_Institution

Sch. of Electr. & Electron. Eng., Nanyang Technol. Univ., Singapore, Singapore

Volume

28

Issue

8

fYear

2013

fDate

Aug. 2013

Firstpage

3870

Lastpage

3881

Abstract

This paper presents a second-order pulsewidth modulation (PWM) feedback loop to improve power supply rejection (PSR) of any open-loop PWM class-D amplifiers (CDAs). PSR of the audio amplifier has always been a key parameter in mobile phone applications. In contrast to class-AB amplifiers, the poor PSR performance has always been the major drawback for CDAs with a half-bridge connected power stage. The proposed PWM feedback loop is fabricated using GLOBALFOUNDRIES´ 0.18-μm CMOS process technology. The measured PSR is more than 80 dB and the measured total harmonic distortion is less than 0.04% with a 1-kHz input sinusoidal test tone.

Keywords

CMOS analogue integrated circuits; audio-frequency amplifiers; bridge circuits; feedback amplifiers; harmonic distortion; power amplifiers; power supply circuits; radiofrequency amplifiers; radiofrequency integrated circuits; CDA power stage; GLOBALFOUNDRIES CMOS process technology; PSR; audio amplifier; class-AB amplifier; frequency 1 kHz; half-bridge connected power stage; input sinusoidal test tone; mobile phone application; open-loop feedback PWM class-D amplifier power stage; power supply rejection; second-order pulsewidth mod- ulation feedback loop; total harmonic distortion; Feedback loop; Hysteresis; Mathematical model; Noise; Power supplies; Pulse width modulation; Threshold voltage; Class-D amplifier (CDA); half-bridge power stage; power supply rejection (PSR); pulsewidth modulation (PWM) feedback loop; total harmonic distortion (THD);

fLanguage

English

Journal_Title

Power Electronics, IEEE Transactions on

Publisher

ieee

ISSN

0885-8993

Type

jour

DOI

10.1109/TPEL.2012.2230027

Filename

6363612