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:
Nov. 21, 2000
Filed:
Sep. 17, 1998
Robert William Spagnoletti, Hertford, GB;
Adrian Paul Sparks, Ongar, GB;
Stephen Richard Foster, Bishop's Stortford, GB;
Nortel Networks Limited, Montreal, CA;
Abstract
The invention provides an improved method and apparatus for detecting the phase difference between a digital data signal and a clock signal. By ensuring that no pulse in the output phase signal is narrow enough to introduce a non-linearity, the present invention avoids a source of non-linearity exhibited in existing phase detectors. In addition, by ensuring that critical timing paths through the circuit contain similar circuit blocks, with similar propagation delays, relative time relationships are preserved from clock and data inputs to XOR inputs. The circuit is therefore largely insensitive to changes in the characteristics of the components so long as they all move together, as they would in an integrated circuit implementation.