Switching-based topologies for high-efficiency audio amplifiers

Author

Saponara, Sergio ; Terreni, Pierangelo

Author_Institution

Dept. of Inf. Eng., Pisa Univ., Italy

Volume

1

fYear

2005

fDate

14-15 July 2005

Firstpage

283

Abstract

The paper describes the PCB-realization of two high-efficiency amplifiers for consumer audio applications. A 35 Wrms output power delivered to an 8 Ω speaker is referred as case study. The first architecture implements a switching amplifier with 3-state pulse width modulation (PWM) while the second solution is an hybrid topology: a linear amplifier is assisted by a switching (buck) converter to increase efficiency for output power higher than 2 Wrms. Compared to conventional linear and class D amplifiers the proposed schemes allow for good performances in terms of harmonic distortion and power efficiency with different trade-offs: the hybrid topology achieves a 0.11% distortion for a 77% power efficiency while the 3-state PWM switching amplifier features a 91% efficiency and a 0.23% distortion.

Keywords

audio-frequency amplifiers; harmonic distortion; network topology; power amplifiers; printed circuits; pulse width modulation; 35 W; 8 ohm; PCB; audio amplifiers; buck converter; harmonic distortion; linear amplifier; pulse width modulation; switching amplifier; switching converter; switching topologies; Filters; Harmonic distortion; High power amplifiers; Portable computers; Power amplifiers; Power generation; Pulse amplifiers; Pulse width modulation; Pulse width modulation inverters; Topology;

fLanguage

English

Publisher

ieee

Conference_Titel

Signals, Circuits and Systems, 2005. ISSCS 2005. International Symposium on

Print_ISBN

0-7803-9029-6

Type

conf

DOI

10.1109/ISSCS.2005.1509909

Filename

1509909