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. 11, 2013
Filed:
Jun. 08, 2011
Applicants:
Khiem Quang Nguyen, Tewksbury, MA (US);
Jie Fu, Shanghai, CN;
Xiaoting Zhu, Shanghai, CN;
Inventors:
Assignee:
Analog Devices, Inc., Norwood, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03L 7/06 (2006.01);
U.S. Cl.
CPC ...
Abstract
A digital PLL may be combined with an analog PLL so that the output of the digital PLL is at a frequency high enough to maintain stability in the analog PLL when an initial reference clock signal is too low to maintain stability in the analog PLL. The digital PLL may include a scaling circuit, such as a frequency divider in the feedback path of the PLL, to generate the higher frequency output signal from the lower frequency reference input signal. The digital PLL may also use an on-chip free run ring oscillator as the clock for the digital PLL engine.