Offset cancellation for audio amplifier
US8907721B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | May 28, 2010 |
| Grant date | Dec 9, 2014 |
| Priority date | — |
| Expiry date | Feb 9, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45438
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An audio amplification circuit is provided having an amplifier that receives an input signal, an output, and a digital control input for receiving a control value in a number n of bits; a comparator having a first input that receives the amplifier's output signal image, a second input that receives a reference potential, and an output; and a thermometer counter having a selection input coupled to the comparator output, and an output delivering an n-bit digital value to the amplifier control input. 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 current identical for all current sources, or no current, as a function of one respective bit of the digital control value received at the control input.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.