Crystal driver circuit with core amplifier having unbalanced tune capacitors
US10574185B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 2017 |
| Grant date | Feb 25, 2020 |
| Priority date | — |
| Expiry date | Jan 12, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03B2201/0266
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A crystal driver circuit for driving a crystal to oscillate at a resonant frequency including an amplifier having an input coupled to an amplifier input node and having an output coupled to an amplifier output node, a current source that provides a core bias current to the amplifier, a first tune capacitor coupled between the amplifier output node and a reference node, and a second tune capacitor coupled between the amplifier input node and the reference node. The first tune capacitor has a first capacitance that is greater than a second capacitance of the second tune capacitor by a capacitance offset that reduces frequency shift during operation. The first and second capacitances have a combined capacitance that achieves an oscillating signal having a target frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.