Intrinsic distortion of a fully differential BD-modulated Class-D amplifier with analog feedback

Cox, Stephen M. and Yu, J. and Goh, W.L. and Tan, M.T. (2013) Intrinsic distortion of a fully differential BD-modulated Class-D amplifier with analog feedback. IEEE Transactions on Circuits and Systems I: Regular Papers, 60 (1). pp. 63-73. ISSN 1549-8328

[img] PDF - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (579kB)

Abstract

This paper presents a mathematical analysis of a fully differential BD-modulated Class-D amplifier with analog feedback, i.e., one having a bridge-tied-load output configuration with negative feedback and ternary PWM signal. Notwithstanding the highly nonlinear nature of

the amplifier's operation, an extremely accurate closed-form expression for the audible output signal is derived and verified based on computer simulations. This expression demonstrates that there exist larger

high-order intrinsic distortions (e.g., 5th-order harmonic distortion and intermodulation distortion) for BD-modulation, compared to that for AD-modulation (binary PWM signal). Furthermore, the 3rd-order harmonic

distortion has a roughly parabolic response as a function of the magnitude of the input signal and reaches its peak when the modulation index of the input signal is around 0.7. Overall, the BD-modulated Class-D amplifier has a larger intrinsic distortion for small input signal but a smaller intrinsic distortion for large input signal,

compared to AD-modulated designs.

Item Type: Article
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.
Schools/Departments: University of Nottingham UK Campus > Faculty of Science > School of Mathematical Sciences
Depositing User: Cox, Stephen
Date Deposited: 09 Feb 2013 16:56
Last Modified: 13 Sep 2016 16:36
URI: http://eprints.nottingham.ac.uk/id/eprint/1886

Actions (Archive Staff Only)

Edit View Edit View