Realization of digital audio amplifier using zero-voltage-switched PWM power converter

Author

Lau, Wing-Hong ; Chung, Henry Shu-Hung ; Wu, C.M. ; Poon, Franki N K

Author_Institution

Dept. of Electron. Eng., City Univ. of Hong Kong, Kowloon, Hong Kong

Volume

47

Issue

3

fYear

2000

fDate

3/1/2000 12:00:00 AM

Firstpage

303

Lastpage

311

Abstract

This paper presents a simple methodology to convert a hard-switched pulse-width-modulated (PWM) H-bridge converter used in a classical digital audio amplifier into a zero-voltage-switching (ZVS) converter. The ZVS is simply achieved by connecting an L-C series branch across the converter output. ZVS occurs during the dead time interval of the PWM signals, giving an effective improvement in the conversion efficiency, output frequency spectrum, and total harmonic distortion. A simplified design procedure is provided for choosing the value of the components. A prototype digital amplifier with an output power of 20 W and switching frequency of 705.6 kHz has been implemented. Experimental results are presented and favorably verified with theoretical predictions

Keywords

PWM power convertors; audio-frequency amplifiers; harmonic distortion; switching circuits; 20 W; 705.6 kHz; L-C series branch; PWM signals; conversion efficiency; dead time interval; design procedure; digital audio amplifier; output frequency spectrum; switching frequency; total harmonic distortion; zero-voltage-switched PWM power converter; Frequency conversion; Joining processes; Power amplifiers; Power generation; Prototypes; Pulse amplifiers; Pulse width modulation; Pulse width modulation converters; Total harmonic distortion; Zero voltage switching;

fLanguage

English

Journal_Title

Circuits and Systems I: Fundamental Theory and Applications, IEEE Transactions on

Publisher

ieee

ISSN

1057-7122

Type

jour

DOI

10.1109/81.841913

Filename

841913