A power-efficient audio amplifier combining switching and linear techniques

Author

Van der Zee, Ronan A R ; Van Tuijl, Ed

Author_Institution

Twente Univ., Enschede, Netherlands

Volume

34

Issue

7

fYear

1999

fDate

7/1/1999 12:00:00 AM

Firstpage

985

Lastpage

991

Abstract

Integrated class-D audio amplifiers are very power efficient but require an external LC reconstruction filter, which prevents further integration. Also due to this filter, large feedback factors are hard to realize, so that the load influences the distortion and transfer characteristics. The 30 W amplifier presented in this paper consists of a switching part that contains a much simpler filter and a linear part that ensures a low distortion and flat frequency response. The switching part of the amplifier was integrated in a BCD process. Combined with a linear part and with a loudspeaker as load, it has a flat frequency response ±0.3 dB, a dissipation that is up to five times lower than a traditional class-AB audio amplifier, and a distortion of <0.02% over power and frequency range

Keywords

audio-frequency amplifiers; electric distortion; frequency response; power amplifiers; switching circuits; 30 W; BCD process; class-D audio amplifiers; flat frequency response; linear techniques; low distortion; power-efficient AF amplifier; switching techniques; Filters; Frequency response; High power amplifiers; Impedance; Loudspeakers; Multiple signal classification; Power amplifiers; Pulse amplifiers; Pulse width modulation; Voltage;

fLanguage

English

Journal_Title

Solid-State Circuits, IEEE Journal of

Publisher

ieee

ISSN

0018-9200

Type

jour

DOI

10.1109/4.772414

Filename

772414