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:
Aug. 18, 2009
Filed:
Aug. 06, 2007
Takeshi Ikeda, Ohta-ku, JP;
Hiroshi Miyagi, Yokohama, JP;
Takeshi Ikeda, Ohta-ku, JP;
Hiroshi Miyagi, Yokohama, JP;
Niigata Seimitsu Co., Ltd., Niigata, JP;
Ricoh Co., Ltd., Tokyo, JP;
Abstract
A frequency synthesizer includes an AND circuit () for detecting whether a frequency synthesizer is in a lock state according to a signal outputted from an Up terminal and a Down terminal of a phase comparator and switching circuits () for switching between presence and absence of connections of constant current circuits () constituting a charge pump circuit () according to the output signal of the AND circuit (). When the AND circuit () has detected a high impedance state of the charge pump circuit (), the switching circuits () disconnects the constant current circuits () by the switching circuits (). Thus, it is possible to eliminate current flowing into the charge pump circuit () without using a control signal from outside such as a power cut signal and an intermittent signal.