System for phase-locking a clock to a digital audio signal embedded in a digital video signal
US6151076A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 10, 1998 |
| Grant date | Nov 21, 2000 |
| Priority date | — |
| Expiry date | Feb 10, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/8106
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system for phase-locking a clock to a digital audio signal embedded within a digital video signal uses an audio extractor, frequency dividers, and an adjusted bandwidth loop filter to prevent phase jitter associated with the digital audio signal preventing the functionality of the phase-lock loop or having unacceptable effects on the generated audio sample frequency signal. Extracted audio samples are divided down and input to a phase detector. The signal is then filtered using a series of loop filters, one of which has an adjusted bandwidth to reject phase jitter. A clock then outputs the generated synthesized audio sample frequency using the output from the series of loop filters, and the synthesized frequency signal is looped back through a second frequency divider to the phase detector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.