A high PSRR Class-D audio amplifier IC based on a self-adjusting voltage reference

Author

Huffenus, Alexandre ; Pillonnet, Gaël ; Abouchi, Nacer ; Goutti, Frédéric ; Rabary, Vincent ; Cittadini, Robert

Author_Institution

Lyon Inst. of Nanotechnol., Univ. of Lyon, Villeurbanne, France

fYear

2010

fDate

14-16 Sept. 2010

Firstpage

118

Lastpage

121

Abstract

In a wide range of applications, audio amplifiers require a large Power Supply Rejection Ratio (PSRR) that the current Class-D architecture cannot reach. This paper proposes a self-adjusting internal voltage reference scheme that sets the bias voltages of the amplifier without losing on output dynamics. This solution relaxes the constraints on gain and feedback resistors matching that were previously the limiting factor for the PSRR. Theory of operation, design and IC evaluation in a Class-D amplifier in CMOS 0.25μm will be shown in this paper. The use of this voltage reference increased the amplifier´s PSRR by 15dB, with only a 140μA increase in current consumption.

Keywords

CMOS integrated circuits; audio-frequency amplifiers; power supply circuits; resistors; IC evaluation; PSRR class-D audio amplifier IC; audio amplifiers; bias voltages; class-D amplifier; class-D architecture; current consumption; feedback resistor; gain resistor; limiting factor; output dynamics; power supply rejection ratio; self-adjusting internal voltage reference scheme; self-adjusting voltage reference; size 0.25 mum; CMOS integrated circuits; Capacitors; GSM; Noise; Preamplifiers; Resistors;

fLanguage

English

Publisher

ieee

Conference_Titel

ESSCIRC, 2010 Proceedings of the

Conference_Location

Seville

ISSN

1930-8833

Print_ISBN

978-1-4244-6662-7

Type

conf

DOI

10.1109/ESSCIRC.2010.5619820

Filename

5619820