Circuit and method for generating temperature-stable clocks using ordinary oscillators
US10992301B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 11, 2020 |
| Grant date | Apr 27, 2021 |
| Priority date | — |
| Expiry date | Mar 11, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L2207/50
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A circuit for generating temperature-stable clocks including first and second crystal oscillators, an input for a reference clock source, a clock output, a first phase acquisition circuit coupled to the first and second crystal oscillators, a second phase acquisition circuit coupled to the input for the reference clock source and to the second crystal oscillator, a first DPLL coupled to the first phase acquisition circuit, a crystal oscillator variation estimator coupled to the first DPLL, a second DPLL coupled to the second phase acquisition circuit and including a phase-frequency detector having a input coupled to the second phase acquisition circuit, a loop filter, a frequency subtractor having an input coupled to the loop filter and an input coupled to the crystal oscillator variation estimator, and a DCO coupled to the frequency subtractor and driving an input of the phase-frequency detector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.