Patent · US Expired

Linearization of a PDM Class-D amplifier

US6771121B2 · kind B2 · utility

7Cited by

7References

37Claims

0Family size

Assignee

DIALOG SEMICONDUCTOR INC. · DE

Inventors

Johan Nilsson · Höllviken, SE
Lars Lennartsson · Torekov, SE
Horst Knoedgen · Munich, DE

Key dates

Filing date	Jan 6, 2003
Grant date	Aug 3, 2004
Priority date	—
Expiry date	Mar 19, 2023

Classification

Technology area (CPC H)Electricity
CPC primaryH03F2200/331
WIPO fieldBasic communication processes
WIPO sectorElectrical engineering

Abstract

A method to linearize the characteristic of a Class-D amplifier is achieved, by compensating for the pulse-area-error, caused by a non-constant power-supply and similar circuit inconsistencies. A Class-D Amplifier typically converts the PDM (Pulse Density Modulated) input signal with a Sigma Delta Modulator and typically uses an H-Bridge as the Class-D power output stage. A fundamental idea is to keep the time-voltage area of every pulse constant. To achieve this, the circuit integrates the power supply voltage, starting with the PDM input pulse and stopping, when the defined time-voltage reference is reached. To compensate not only for power supply variations, but also for e.g. the voltage drop across the output devices, the integrator's input would be more directly reference to the actual voltage across the output load.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.