Fast wakeup for crystal oscillator
US10594325B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 6, 2018 |
| Grant date | Mar 17, 2020 |
| Priority date | — |
| Expiry date | Aug 16, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L2207/06
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Techniques are described for fast wakeup of a crystal oscillator circuit. Embodiments operate in context of a crystal oscillator coupled with a phase-locked loop (PLL). For example, prior to entering sleep mode, embodiments retain a previously obtained coarse code used to coarse-tune a voltage controlled oscillator of the PLL. On wakeup, the PLL is configured in a chirp mode, in which the retained coarse code and a sweep voltage are used to generate a chirp signal at, or close to, a target stimulating frequency for the crystal oscillator. The chirp signal can be used to inject energy into the crystal oscillator, thereby causing the crystal oscillator to move from sleep mode to steady state oscillation relatively quickly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.