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:
Jun. 15, 2010
Filed:
Nov. 13, 2008
Applicants:
Manabu Oyama, Kyoto, JP;
Daisuke Uchimoto, Kyoto, JP;
Inventors:
Manabu Oyama, Kyoto, JP;
Daisuke Uchimoto, Kyoto, JP;
Assignee:
Rohm Co., Ltd., , JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G05F 1/10 (2006.01);
U.S. Cl.
CPC ...
Abstract
A pulse frequency modulator generates a pulse signal having a fixed duty ratio and a frequency which is adjusted such that a feedback voltage corresponding to the output voltage of a charge pump circuit is coincident with a predetermined first reference voltage. A driver, on receiving the pulse signal, turns on a first or second group of switches during the time periods corresponding to the high time periods of the pulse signal and turns on the other ones of the first and second group of switches during the time periods corresponding to the low time periods of the pulse signal.