Phase locked loop system having locking and tracking modes of operation
US7755437B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 24, 2005 |
| Grant date | Jul 13, 2010 |
| Priority date | — |
| Expiry date | May 5, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/1075
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An embodiment pertains to a phase locked loop (PLL) circuit. The PLL includes a voltage controlled oscillator which outputs a signal at a desired frequency. A phase detector is coupled to an output from the voltage controlled oscillator. The phase detector compares the phase of a signal output from the voltage controlled oscillator (VCO) with the phase of a reference signal. A loop filter is coupled to the VCO and the phase detector. The loop filter has a locking mode of operation for locking the phase of the VCO signal to the phase of the reference signal. The loop filter can subsequently be placed in a tracking mode of operation which adjusts the phase of the VCO signal to track the phase of the reference signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.