Class D amplifier power stage with PWM feedback loop

Lam, C.K.; Tan, M.T.; Cox, Stephen M.; Yeo, K.S.

Abstract

This paper presents a Second-Order Pulse Width 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 half-bridge connected power stage. The proposed PWM feedback loop is fabricated using GLOBALFOUNDRIES' (GF’s) 0.18 µm CMOS process technology. The measured PSR is more than 80 dB and the measured Total Harmonic Distortion (THD) is less than 0.04% with a 1 kHz input sinusoidal test tone.

Citation

Lam, C., Tan, M., Cox, S. M., & Yeo, K. Class D amplifier power stage with PWM feedback loop. IEEE Transactions on Power Electronics, 28(8), https://doi.org/10.1109/TPEL.2012.2230027

• Journal Article Type: Article
• Deposit Date: Feb 9, 2013
• Journal: IEEE Transactions on Power Electronics
• Print ISSN: 0885-8993
• Electronic ISSN: 1941-0107
• Publisher: Institute of Electrical and Electronics Engineers
• Peer Reviewed: Peer Reviewed
• Volume: 28
• Issue: 8
• DOI: https://doi.org/10.1109/TPEL.2012.2230027
• Public URL: https://nottingham-repository.worktribe.com/output/1004704
• Publisher URL: http://dx.doi.org/10.1109/TPEL.2012.2230027
• Additional Information: (c) 2013 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.