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:
Jan. 08, 2002

Filed:

Jan. 26, 2001
Applicant:
Inventors:

Kyuichi Takimoto, Kasugai, JP;

Toshiyuki Matsuyama, Kasugai, JP;

Yoshihiro Nagaya, Kasugai, JP;

Assignee:

Fujitsu Limited, Kawasaki, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G05F 1/40 ;
U.S. Cl.
CPC ...
G05F 1/40 ;
Abstract

A DC-DC converter generally includes a supply circuit, a charge circuit, and a control unit connected to the charge circuit. The charge circuit receives the input current and supplying a charge current to the battery. The control unit controls the charge current according to the results of comparisons between various currents and voltages and corresponding threshold levels. The control unit, which may be constructed on a single-chip semiconductor substrate, includes a differential charge controller, a charge current controller, a charge voltage controller, and a dynamic charge controller. These elements respectively compare the input current, the charge current, the charge voltage and an input voltage from the external DC power supply with a threshold values and control the charge current and charge voltage according to a result of the comparisons.


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