High-frequency low-gain ring VCO for clock-data recovery in high-speed serial interface of a programmable logic device
US7956695B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 23, 2010 |
| Grant date | Jun 7, 2011 |
| Priority date | — |
| Expiry date | Mar 23, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K3/0322
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A voltage-controlled oscillator operates at high frequency without high gain by dividing the frequency range into a plurality of subranges, which preferably are substantially equal in size. Within any subrange, the full extent of variation in the control signal changes the frequency only by the extent of the subrange. The gain is thus substantially equal to the gain one would expect for the full frequency range, divided by the number of subranges. The subrange may be selected manually, or by an initial calibration process. In one embodiment, the oscillator includes a voltage-to-current converter and a current-controlled oscillator, with a current mirror arrangement. In that embodiment, selection of the subrange may be controlled by turning on the correct number of current legs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.