Audio amplifier offset reduction using digital input/output comparisons
US8525710B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 2010 |
| Grant date | Sep 3, 2013 |
| Priority date | — |
| Expiry date | Dec 18, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M3/50
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An offset correction circuit removes DC offset from an analog audio output signal by comparing transitions of digital audio values to which the analog output signal is related to the output of a monitor that monitors the analog output signal. The monitor may be a zero-crossing detector and the transitions of the digital signal that are compared may be transitions of the most-significant bit (MSB) of the digital audio values. A filtering algorithm or filter circuit may be used to average a result of the comparison of the transitions, so that the offset is slowly and accurately removed. A chopped or autozero comparator may be used to further reduce error in the offset determination.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.