Search International and National Patent Collections

. (WO2010136578) OFFSET CANCELLATION FOR AUDIO AMPLIFIER

Pub. No.:    WO/2010/136578    International Application No.:    PCT/EP2010/057444
Publication Date: Fri Dec 03 00:59:59 CET 2010 International Filing Date: Sat May 29 01:59:59 CEST 2010
IPC: H03F 3/45
H03F 3/72
Applicants: ST-Ericsson (Grenoble) SAS
ST-ERICSSON SA
CELLIER, Rémy
AMIARD, François
Inventors: CELLIER, Rémy
AMIARD, François
Title: OFFSET CANCELLATION FOR AUDIO AMPLIFIER
Abstract:
An audio amplification circuit comprises an amplifier (10) having an input for receiving an input signal (Vin), an output, and a digital control input for receiving a control value in a number n of bits, a comparator (20) having a first input coupled to the output of the amplifier for receiving an image of the output signal of the amplifier, a second input receiving a reference potential, and an output, and a thermometer counter (30) having a selection input coupled to the output from the comparator, and an output delivering an n-bit digital value (COR) which is provided to the control input of the amplifier. The amplifier comprises a differential input stage having a first and a second differential branch, each traversed by a bias current, the current in the first branch being modifiable by n basic current sources which each deliver either a basic current which is identical for all basic current sources, or no current, as a function of the binary value of one of the respective bits of the digital control value received at the control input.