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:
Jun. 27, 2006
Filed:
Jun. 28, 2004
Doug Frey, Bethlehem, PA (US);
Axel Thomsen, Austin, TX (US);
Ligang Zhang, Austin, TX (US);
Silicon Laboratories Inc., Austin, TX (US);
Abstract
A noise cancellation signal is generated for a fractional-N phase-locked loop by supplying a divide value to a first delta sigma modulator and generating a divide control signal in a first delta sigma modulator to control a divide value of a feedback divider in the phase-locked loop. The first delta sigma modulator integrates an error term indicative of a difference between a value of the generated divide control signal and the divide value supplied to the first delta sigma modulator. A phase error cancellation signal is generated by quantizing the integrated error term using a second delta sigma modulator. The error term can be used by the second delta sigma modulator while quantizing the integrated error term, thereby limiting the low pass filter effects of the second delta sigma modulator in the cancellation signal.