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:
Jun. 22, 2010
Filed:
Jul. 10, 2006
Chih-chien Huang, Yunlin Hsien, TW;
Chien-ming Chen, Hsin-Chu, TW;
Chih-Chien Huang, Yunlin Hsien, TW;
Chien-Ming Chen, Hsin-Chu, TW;
Mediatek Inc., Hsin-Chu, TW;
Abstract
The invention provides a PLL device comprising a PFD unit, a charging pump circuit, a loop filter, an oscillator, a feedback divider and a current compensation circuit. The PFD unit measures a phase and a frequency difference between a reference clock signal and a feedback clock signal of the PLL device to output a difference signal UP and a difference signal DN. The charging pump circuit receives and transfers the difference signals UP and DN into a current. The loop filter receives and transfers the current into a voltage. The oscillator receives the voltage and outputs an output signal. The feedback divider having a parameter N receives the output signal to generate the feedback clock signal according to the parameter N, wherein a frequency of the feedback clock signal is N times a frequency of the output signal. When the reference clock signal leads the feedback clock signal, the current compensation circuit outputs a compensation current to the loop filter.