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:
Jan. 10, 2012
Filed:
Aug. 26, 2009
Zheng Ying, Shanghai, CN;
Huang Zhang Xu, Shanghai, CN;
Zheng Ying, Shanghai, CN;
Huang Zhang Xu, Shanghai, CN;
Abstract
Method and apparatus for adding jitter to an oscillator for reducing EMI are disclosed An oscillator circuit includes an oscillator configured to generate a first clock having a first frequency and a frequency jitter circuit including a charge pump configured to charge and discharge first and second capacitors repeatedly for obtaining a time-varying voltage having a second frequency. The time-varying voltage is coupled to the oscillator to vary the first frequency within a frequency range. The charge pump includes a first switch for coupling the first capacitor to a voltage source and a second switch for coupling the first capacitor to the second capacitor. A charge transfer between the first and second capacitors is configured to provide the time-varying voltage.