Title :
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
fDate :
3/1/2000 12:00:00 AM
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;
Journal_Title :
Circuits and Systems I: Fundamental Theory and Applications, IEEE Transactions on
