Clock signal extraction apparatus using VCO having plurality of selectable phase shifted outputs
US5528198A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 1, 1995 |
| Grant date | Jun 18, 1996 |
| Priority date | — |
| Expiry date | Jun 1, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/087
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A plurality of clock signals at an identical frequency but with different phases are oscillated by a voltage-controlled oscillator beforehand, and selection is made of one of the clock signals whose phase is closest to that of the data signal each time the data signal rises. In parallel with the selection of phase, a phase/frequency comparison is made between any one of the clock signals output from the voltage-controlled oscillator and the selected clock signal. After the comparison, the oscillation frequency of the voltage-controlled oscillator is converted for their matching. This matching allows acquisition of a clock signal with the closest phase immediately after arrival of the data signal, and acquisition of an extraction clock signal with the frequency and phase matched in a short time by parallel conversion of the oscillation frequency of the voltage-controlled oscillator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.