The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 11, 2023
Filed:
Jun. 29, 2022
Silicon Laboratories Inc., Austin, TX (US);
Mohamed M. Elkholy, Cedar Park, TX (US);
Mustafa Koroglu, Austin, TX (US);
Wenhuan Yu, Austin, TX (US);
Silicon Laboratories Inc., Austin, TX (US);
Abstract
A frequency synthesizer on an integrated circuit provides a local oscillator (LO) signal for RF operations and also functions as an injection clock signal source during crystal oscillator startup. The integrated circuit goes into a sleep mode in which the crystal oscillator is off and responsive to a wakeup event the crystal oscillator starts up again using the injection clock signal sourced from the frequency synthesizer. Parameters that cause the injection clock signal to match the crystal oscillator frequency are stored. The frequency synthesizer includes a phase-locked loop having an LC oscillator. A digital to analog converter controls the LC oscillator during injection. During an initial power up of the integrated circuit, a PLL in the frequency synthesizer locks to the crystal oscillator frequency to determine the parameters to store for injection.