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. 15, 2011
Filed:
Aug. 30, 2009
Huan-ke Chiu, Hsinchu County, TW;
Tzu-chan Chueh, Taipei County, TW;
Huan-Ke Chiu, Hsinchu County, TW;
Tzu-Chan Chueh, Taipei County, TW;
Industrial Technology Research Institute, Hsinchu, TW;
Abstract
A digital phase-locked loop and a digital phase-frequency detector thereof are provided. The digital PFD includes a divisor switch unit, a low-resolution phase-error detecting unit, an accumulating unit, a high-resolution phase-error detecting unit, a constant unit, and a selector. The divisor switch unit receives and removes partial pulses of a feedback signal for obtaining a feedback clock. The low-resolution phase-error detecting unit detects phase error between a reference signal and the feedback clock to obtain a phase-error pulse width. The accumulating unit accumulates the feedback signal during the phase-error pulse width for obtaining an output selection signal. The high-resolution phase-error detecting unit detects phase error between the reference signal and the feedback signal to obtain a phase-error value. The constant unit provides at least one constant value. The selector selects and outputs one of the phase-error value and the constant value according to the output selection signal.