VCO gain self-calibration for low voltage phase lock-loop applications
US6552618B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 13, 2000 |
| Grant date | Apr 22, 2003 |
| Priority date | — |
| Expiry date | Dec 13, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/18
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A phase-locked loop (PLL) circuit having a voltage-controlled oscillator (VCO) is automatically calibrated for VCO center frequency and VCO gain during power up or responsive to a calibration signal. The VCO has several input voltage versus output frequency operating curves. During a calibration phase, proper VCO center frequency is selected by selecting one of the operating curves. VCO gain is then determined using the selected VCO operating curve. If the value of VCO gain is not within predetermined limits, VCO gain is adjusted accordingly, and the process of selecting a VCO operating curve and determining VCO gain is repeated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.