Time-domain analysis of intermodulation distortion of closed-loop Class D amplifiers

Yu, J.; Tan, M.T.; Cox, Stephen M.; Goh, W.L.

Abstract

This paper presents a time-domain analysis of the intermodulation distortion (IMD) of a closed-loop Class D amplifier with either 1st-order or 2nd-order loop filter. The derived expression for the IMD indicates that there exist significant 3rd-order intermodulation products (3rd-IMPs) within the output spectrum, which may lead to even greater distortion than the intrinsic harmonic components. In addition, the output expressions are compact, precise and suitable for hand calculation, so that the parametric relationships between the IMD and the magnitude and frequency of the input signals, as well as the effect of the loop filter design, are straightforwardly investigated. In order to accurately represent the IMD performance of Class D amplifiers, a modified testing setup is introduced to account for the dominantly large 3rd-IMPs when the ITU-R standard is applied.

Citation

Yu, J., Tan, M., Cox, S. M., & Goh, W. (2012). Time-domain analysis of intermodulation distortion of closed-loop Class D amplifiers. IEEE Transactions on Power Electronics, 27(5), https://doi.org/10.1109/TPEL.2011.2171196

• Journal Article Type: Article
• Publication Date: Jan 1, 2012
• Deposit Date: Feb 9, 2013
• Publicly Available 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: 27
• Issue: 5
• DOI: https://doi.org/10.1109/TPEL.2011.2171196
• Public URL: https://nottingham-repository.worktribe.com/output/1009463
• Publisher URL: http://dx.doi.org/10.1109/TPEL.2011.2171196
• 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.