Crystal oscillator startup time optimization
US10601369B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 11, 2018 |
| Grant date | Mar 24, 2020 |
| Priority date | — |
| Expiry date | Jul 11, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03B2200/0094
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An oscillation circuit including a crystal interface, a crystal amplifier, a level detector, a timing circuit, and a controller. When activated, the crystal amplifier drives a crystal coupled to the crystal interface to establish oscillation, and the level detector indicates when a target amplitude is detected. The controller activates the crystal amplifier and uses the timing circuit and the level detector to measure a startup time of oscillation. The measured startup time is used in calculating a wake up time from a sleep mode in time to perform an operation at a scheduled time. The startup time may be adjusted or averaged and may be remeasured with temperature change. A method of minimizing startup time of a crystal oscillator includes measuring startup time for determining a delay value for programming a wakeup circuit. Robust startup settings may be used in the event of startup failure due to a sleepy crystal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.