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:
Mar. 09, 2010
Filed:
Dec. 17, 2004
Applicants:
Kok Yoong Foo, Bayan Lepas, MY;
Tze Haw Liew, Sarawak, MY;
Joo Ming Too, Kedah, MY;
Inventors:
Assignee:
Altera Corporation, San Jose, CA (US);
Primary Examiner:
Int. Cl.
CPC ...
H03K 3/017 (2006.01); H03K 5/04 (2006.01); H03K 7/08 (2006.01);
U.S. Cl.
CPC ...
Abstract
Circuits, methods, and apparatus that provide the improvement or recovery of a duty cycle of a clock signal. One embodiment of the present invention receives a clock signal that may have a degraded duty cycle. The frequency of the clock signal is divided by two. The frequency-divided signal is delayed in order to generate two signals that are phase shifted from one another by 90 degrees. These signals are then exclusive-ORed together to generate a recovered clock. A control loop is provided to adjust the phase shift between the signals to be approximately 90 degrees.