Class-AB high-swing CMOS power amplifier

Author

Mistlberger, F. ; Koch, R.

Author_Institution

Siemens AG, Munich, Germany

Volume

27

Issue

7

fYear

1992

fDate

7/1/1992 12:00:00 AM

Firstpage

1089

Lastpage

1092

Abstract

A power amplifier for a loudspeaker and the earpiece of a telephone subset, integrated in the codec chip ARCOFI-SP (audio ringing codec filter featuring speakerphone function), are presented. The ARCOFI-SP is part of a subscriber telephone chip set. The analog section of the receive path comprises a low-noise programmable gain microphone amplifier with a maximum gain of 30-dB followed by a 16-b second-order sigma-delta analog-to-digital (A/D) converter. The analog section of the transmit path consists of two 16-b second-order sigma-delta D/A converters, one driving a pair of handset amplifiers for 200- Omega differential load and the other one a pair of loudspeaker amplifiers for 50- Omega differential load. The loudspeaker amplifier is described. A digital signal processor calculates the filter functions and handles frequency and tone generation. The amplifier has 1.2-mA quiescent current, 64-mA peak current, and >60 dB S/THD with 3.2-V output swing into a 25- Omega load.

Keywords

CMOS integrated circuits; audio-frequency amplifiers; codecs; power amplifiers; telephone sets; 1.2 mA; 3.2 V; 64 mA; CMOS; audio ringing codec filter; class AB; codec chip ARCOFI-SP; digital signal processor; filter functions; handset amplifiers; loudspeaker amplifiers; output swing; peak current; power amplifier; programmable gain microphone amplifier; quiescent current; sigma-delta A/D converter; speakerphone function; telephone subset; tone generation; Codecs; Delta-sigma modulation; Differential amplifiers; Filters; High power amplifiers; Loudspeakers; Low-noise amplifiers; Microphones; Power amplifiers; Telephony;

fLanguage

English

Journal_Title

Solid-State Circuits, IEEE Journal of

Publisher

ieee

ISSN

0018-9200

Type

jour

DOI

10.1109/4.142606

Filename

142606