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:
Jul. 04, 2006
Filed:
Apr. 29, 2004
Masakatsu Suda, Tokyo, JP;
Satoshi Sudou, Tokyo, JP;
Toshiyuki Okayasu, Tokyo, JP;
Advantest Corporation, Tokyo, JP;
Abstract
A variable delay circuit includes plural stages of first variable delay elements coupled in series for sequentially delaying a reference clock signal or a data signal, a second variable delay element coupled in parallel to the plural stages of first variable delay elements for delaying the reference clock signal, a phase comparator for comparing the phase of the reference clock signal delayed by the plural stages of first variable delay elements with the phase of the reference clock signal delayed by the second variable delay element, and a delay amount control unit for controlling the delay amount of each of the plural stages of first variable delay elements based on the comparison result of the phase comparator in order that the phase of the reference clock signal delayed by the plural stages of first variable delay elements is substantially the same as the phase of the reference clock signal delayed by the second variable delay element after predetermined cycles.