Oscillator tuning for phase-locked loop circuit
US7969248B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 2009 |
| Grant date | Jun 28, 2011 |
| Priority date | — |
| Expiry date | Sep 23, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/113
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In one example, a method of tuning an oscillator of a phase-locked loop (PLL) circuit includes adjusting a coarse control signal to select one of a plurality of frequency tuning curves of the oscillator. The method includes adjusting a fine control signal to select a position on the selected frequency tuning curve. A frequency of the oscillator is determined by the coarse control signal and the fine control signal. The method includes attempting to detect a lock between a feedback signal and a reference signal. A frequency of the feedback signal is determined by the frequency of the oscillator. The method includes comparing the fine control signal to a reference value if the lock is detected. The method includes adjusting the coarse control signal to select a different one of the frequency tuning curves if the selected position on the selected frequency tuning curve is outside a desired tuning range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.