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.

Date of Patent:
Apr. 28, 2015

Filed:

Feb. 12, 2013
Applicants:

Fujitsu Limited, Kawasaki-shi, Kanagawa, JP;

Fujitsu Semiconductor Limited, Yokohama-shi, Kanagawa, JP;

Inventors:

Win Chaivipas, Kawasaki, JP;

Masazumi Marutani, Yokohama, JP;

Daisuke Yamazaki, Yokohama, JP;

Assignees:

Fujitsu Limited, Kawasaki, JP;

Fujitsu Semiconductor Limited, Yokohama, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03L 7/085 (2006.01); H03L 7/089 (2006.01); H03L 7/00 (2006.01); H03L 7/14 (2006.01); H03L 7/093 (2006.01); H03L 7/099 (2006.01);
U.S. Cl.
CPC ...
H03L 7/00 (2013.01); H03L 7/0994 (2013.01); H03L 7/0991 (2013.01); H03L 7/146 (2013.01); H03J 2200/10 (2013.01); H03L 7/093 (2013.01); H03L 7/099 (2013.01);
Abstract

A digitally controlled oscillator has a high-order ΔΣ modulator configured to be of at least an order higher than a first order and configured to input a digital control signal and output a pseudorandom digital output signal, a first-order ΔΣ modulator configured to input the pseudorandom digital output signal and generate a control pulse signal including a pulse width corresponding to the pseudorandom digital output signal, a low pass filter configured to pass a low frequency component of the control pulse signal, and an oscillator configured to generate a high-frequency output signal whose frequency is controlled based on the control pulse signal outputted by the low pass filter so as to be a frequency corresponding to the digital control signal.


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