Audio clock regenerator with precisely tracking mechanism
US8063986B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 4, 2007 |
| Grant date | Nov 22, 2011 |
| Priority date | — |
| Expiry date | Sep 21, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/4305
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In an HDMI system, the clock regenerator proposed by the HDMI specification may suffer external noise because the input clock of a phase lock loop circuit in a sink device of the HDMI system is too slow. This slow input clock causes the phase lock loop circuit unable to adjust and reduce the jitter of an audio clock regenerated in the sink device. Therefore, one embodiment of the present invention provides a clock regenerator to extract the relationship between the regenerated audio clock and a video clock received by the sink device from other source devices. The clock regenerator may comprise a phase lock loop circuit, a recovery circuit, a crystal oscillator and a tracking circuit. The crystal oscillator generates a crystal clock. The phase lock loop circuit receives the crystal clock and regenerates an audio clock. The recovery circuit extracts the relationship between the audio clock and the received video clock. The tracking circuit tunes the frequency of the crystal clock based on the extracted relationship.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.