Phase-locked loop with static phase offset compensation
US6043715A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 1, 1998 |
| Grant date | Mar 28, 2000 |
| Priority date | — |
| Expiry date | Sep 1, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/087
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A phase-locked loop (PLL) has a master circuit configured to a slave circuit. The slave circuit has a phase detector, a charge pump, a loop filter, and a voltage-controlled oscillator configured to operate as a closed-loop PLL. The master circuit has a phase detector and a charge pump that are similar to the corresponding components in the slave circuit. The master circuit is configured to receive two input signals with zero phase offset. As such, any net current charge generated by the master charge pump will be indicative of mismatch within the master phase detector and charge pump, and therefore, by analogy, indicative of mismatch within the slave phase detector and charge pump, as well. A voltage signal generated by the master circuit is applied to control the generation of currents by the slave charge pump in such a way as to compensate for static phase offset that would otherwise exist in the slave circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.