Frequency detector including a variable delay filter
US7502434B2 · kind B2 · utility
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4References
48Claims
0Family size
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Key dates
| Filing date | Mar 30, 2004 |
| Grant date | Mar 10, 2009 |
| Priority date | — |
| Expiry date | Sep 25, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/113
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A frequency detector and frequency-locked loop suitable for use in a clock recovery circuit are disclosed. The detector is linear, and can be used in implementing a loss of lock indicator. Variable delay filtering permits the frequency detector to be less sensitive to data fluctuations, and random or pseudo random addition of jitter helps address low gain in the data stream. A VCO controller cycles through a number of control states and provides varying levels of gain, dither and delay during each of the control states.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.