VCO initial frequency calibration circuit and method therefore
US7742553B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 2005 |
| Grant date | Jun 22, 2010 |
| Priority date | — |
| Expiry date | May 10, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L2207/06
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A device and a method for processing high data rate serial data includes a VCO initial frequency calibration circuit. The circuit includes a frequency detection block for indicating a difference between a reference clock and a divided VCO clock, a frequency calibration block that produces a digital output signal based upon the difference between the reference clock and the divided VCO clock, and a digital-to-analog converter for producing an analog VCO adjust signal. The frequency detection block produces a plurality of signals based upon the reference clock and the divided VCO clock. A plurality of user selected inputs selects a frequency detection lock range and hysteresis range and a coarse loop open calibration lock and hysteresis range. The frequency calibration block implements a state machine for producing the digital output signal that sets the initial operating frequency then adjusts the frequency of the VCO clock.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.