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. 04, 2014
Filed:
Sep. 12, 2012
Yu-li Hsueh, Taipei, TW;
Chih-hsien Shen, Zhubei, TW;
Jing-hong Conan Zhan, HsinChu, TW;
Mediatek Inc., Hsin-Chu, TW;
Abstract
An apparatus for duty cycle calibration includes an input calibration circuit, a delay chain, a first comparator, and a second comparator. The input calibration circuit calibrates an input clock signal according to a first control signal so as to generate an input calibration clock signal. The delay chain includes a plurality of delay units coupled in series, and delays the input calibration clock signal so as to generate a first delay clock signal and a second delay clock signal. At least two of the delay units each have an adjustable delay time which is controlled according to a second control signal. The first comparator compares the input calibration clock signal with the first delay clock signal so as to generate the first control signal. The second comparator compares the input calibration clock signal with the second delay clock signal so as to generate the second control signal.