Three-state phase-detector/charge pump with no dead-band offering tunable phase in phase-locked loop circuits
US5917352A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1997 |
| Grant date | Jun 29, 1999 |
| Priority date | — |
| Expiry date | Sep 30, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/0891
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The present invention is directed to providing a phase detector capable of establishing phase-locked-loop operation in a highly accurate and reliable manner. For example, exemplary embodiments detect a phase difference between at least two input signals to phase lock the input signals to one another. Exemplary embodiments include two phase detectors each of which receives the two input signals (e.g., three-state phase detectors), and each of which is forced to operate outside of its dead-band region by introducing predetermined phase delays for its inputs. Each of the two phase detectors detects a phase difference between its respective inputs. The two phase differences are then combined to produce a composite output signal formed as a net charge proportional to the net phase difference detected by the two phase detectors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.