Crystal-oscillator circuit
US8228131B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 12, 2011 |
| Grant date | Jul 24, 2012 |
| Priority date | — |
| Expiry date | Jan 12, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L1/022
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In a crystal-oscillator circuit having a quartz crystal unit, further stabilization of output frequency change at a time of startup of the power supply is achieved. A crystal-oscillator circuit having a quartz crystal unit includes a first variable-capacitance element, which forms an oscillation loop with the quartz crystal unit, and a temperature compensation circuit which provides a first control signal for the first variable-capacitance element to compensate for a temperature characteristic of the quartz crystal unit. In addition, the crystal-oscillator circuit includes a second variable-capacitance element group, and a time constant circuit which provides a time constant signal, which changes with a predetermined time constant, for the second variable-capacitance element group as a second control signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.