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:
May. 22, 2007
Filed:
Apr. 08, 2005
Hidekiyo Ozawa, Kasugai, JP;
Hidenobu Ito, Kasugai, JP;
Chikara Tsuchiya, Kasugai, JP;
Yasushige Ogawa, Kasugai, JP;
Hidekiyo Ozawa, Kasugai, JP;
Hidenobu Ito, Kasugai, JP;
Chikara Tsuchiya, Kasugai, JP;
Yasushige Ogawa, Kasugai, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A DC-DC converter for generating power supply voltage differing from input voltage, while operating a semiconductor circuit at a predetermined speed regardless of differences between devices or changes in the operation environment. An output voltage control circuit compares an oscillation signal, which is provided from a ring oscillator of the semiconductor circuit, with a triangular wave signal, which is provided from an oscillator of the DC-DC converter, and changes the output voltage of the DC-DC converter in accordance with the comparison result. This substantially equalizes the oscillation signal of the ring oscillator with the triangular wave signal, which functions as a reference signal, and operates the semiconductor circuit at a speed that is in accordance with the triangular wave signal.