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:
Mar. 06, 2007

Filed:

Apr. 13, 2004
Applicant:

Tomonari Katoh, Osaka, JP;

Inventor:

Tomonari Katoh, Osaka, JP;

Assignee:

Ricoh Company, Ltd., Tokyo, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G05F 1/573 (2006.01);
U.S. Cl.
CPC ...
Abstract

A DC—DC converter is disclosed that includes a constant voltage circuit outputting a first voltage, a charge pump circuit outputting a second voltage, a current detection circuit converting the output current of the constant voltage circuit into a third voltage and outputting the third voltage, a first detection circuit detecting the first voltage and outputting a first detection voltage proportional thereto, a first overcurrent protection circuit comparing the third voltage and the first detection voltage and reducing the output first voltage and current of the constant voltage circuit when the third voltage exceeds the first detection voltage, a second detection circuit detecting the second voltage and outputting a second detection voltage proportonal thereto, and a second overcurrent protection circuit comparing the third voltage and the second detection voltage and reducing the output first voltage and current of the constant voltage circuit when the third voltage exceeds the second detection voltage.


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