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.

Date of Patent:
Feb. 24, 2009

Filed:

Sep. 16, 2005
Applicants:

Jinghui LU, Austin, TX (US);

Yiqin Chen, Austin, TX (US);

Inventors:

Jinghui Lu, Austin, TX (US);

Yiqin Chen, Austin, TX (US);

Assignee:

Xilinx, Inc., San Jose, CA (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04L 27/00 (2006.01);
U.S. Cl.
CPC ...
Abstract

A clock recovery circuit includes a crossover adjustment circuit operable to adjust a crossover point to adjust a corresponding duty cycle. The adjustment circuit comprises a feedback adjustment combining element which is implemented as summing elements and a crossover point control clock amplifier, an operational amplifier with a resistor in place of a low pass filter at an input of the operational amplifier and feedback driver. The summing element within the feedback adjustment combining element combines input clocks with feedback signals, the crossover point control clock amplifier includes adjustment driver, the two cross coupled PMOS along with the resistor connected between them, reshape input clocks, adjust cross over point and provide output clocks with DCD corrected. A modified Miller capacitor comprising a resistor in series with a capacitor across a drain and gate of a cascode transistor pair is utilized in an output stage to adjust corner frequencies.


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