Circuit, system, and method for fine tuning crystal frequency accuracy
US7352255B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 13, 2004 |
| Grant date | Apr 1, 2008 |
| Priority date | — |
| Expiry date | Mar 31, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/099
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Circuits, systems, and methods for fine tuning crystal frequency accuracy are disclosed. One such circuit fine tunes crystal frequency accuracy with a tunable fractional capacitance. The circuit includes an effectively constant capacitance coupled, e.g., fixedly, with the crystal. A second capacitance is controllably coupleable with the crystal. A switching device is controllable for switchably coupling the second capacitance with the crystal. An effective capacitance value associated with the second capacitance varies according to a time associated with that switchable coupling. The crystal resonating frequency changes according to a capacitive loading thereof, which includes the first capacitance and the effective capacitance value of the second capacitance, effectively time multiplexed therewith.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.