Clock shaping device and electronic instrument using the same
US7057430B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 2004 |
| Grant date | Jun 6, 2006 |
| Priority date | — |
| Expiry date | Mar 3, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J3/0688
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A clock shaping device includes a first clock signal selection portion that selects between a reception clock signal and a back-up clock signal based on a detected loss in the reception clock signal. A second clock signal selection portion selects between a clock signal received from the first clock signal selection portion and a clock signal received from a quartz crystal oscillation circuit based on a detected loss in the back-up clock signal. A voltage controlled oscillation circuit has a frequency that varies with a control voltage being supplied and outputs a feedback loop output signal. A phase comparison portion generates a phase difference signal based on a comparison between the feedback loop output signal and a clock signal outputted from the second clock signal selection portion. A loop filter smoothes the phase difference signal and outputs the phase difference signal in the form of the control voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.