Single-chip audio system volume control circuitry and methods
US6628999B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 1998 |
| Grant date | Sep 30, 2003 |
| Priority date | — |
| Expiry date | Feb 26, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02D30/70
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An audio system 100 includes circuitry 116 for generating an audio data stream and circuitry 103 for generating digital words defining a volume control level. System 100 also includes volume control circuitry 5000 for controlling the amplitude of the audio data stream in response to the digital words. Volume control circuitry 5000 includes a master register 5001 for holding digital words received from circuitry for generating 116 and a slave register 5002 for holding a digital word selectively transferred from master register 5001 in response to an enable signal. Output control circuitry 5005, 5006 and 5007 receive the audio data stream and apply a preselected gain defined by the digital word held in slave register 5002. Volume control circuitry 5000 also includes circuitry 5003, 5004 for generating the enable signal when a digital word held in the master register 5001 changes and the audio data stream output from ouput control circuitry 5005, 5006, 5007 reaches a zero crossing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.