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:
May. 31, 2016
Filed:
Aug. 17, 2015
Cadence Design Systems, Inc., San Jose, CA (US);
Ali Ulas Ilhan, Elkridge, MD (US);
Eric Naviasky, Elkridge, MD (US);
Cadence Design Systems, Inc., San Jose, CA (US);
Abstract
In a clock recovery system, a phase detector detects a phase error in an incoming data signal, which it outputs as a differential pair of voltage signals representing positive and negative errors, respectively. A proportional filter generates a proportional offset from the phase error, also as a differential pair of voltage signals. An integral filter generates an integral offset from the proportional offset, using positive and negative voltage controlled oscillators to generate oscillating integral offset signals, and an accumulator to increment or decrement a digital counter for each cycle of the integral offset signals. A first, fractional phase interpolator operating over a ninety-degree range adjusts the phase of an initial clock signal to generate an intermediate clock signal, according to the proportional offset. A second phase interpolator adjusts the phase of the intermediate clock signal to generate an adjusted clock signal, according to the integral offset.