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:
Mar. 12, 2013
Filed:
Aug. 25, 2009
Takeshi Hamada, Tokyo, JP;
Takeshi Hamada, Tokyo, JP;
Asahi Kasei Microdevices Corporation, Tokyo, JP;
Abstract
Provided is a charge pump circuit which is preferably used for reducing noise generated when electric charges are accumulated in a capacitor of the charge pump circuit. A load driving systemincludes a charge pump circuit, a clock generation circuit, an amplifier circuit, and a load. The charge pump circuitincludes capacitors Cand C, a transistor PTrwhich is a P-channel MOS transistor and controls current supply to the C, switching elements SWto SW, and a supply current control circuit. The charge pump circuitswitches the SWto SW, to thereby perform the accumulation of electric charges to the Cand the transfer of the accumulated electric charges to the Cfor generating a negative power source. The supply current control circuitincludes a transistor PTr, a switching element SW, and a transistor NTrwhich forms a current mirror with a transistor NTrwhich constitutes an output stage of the amplifier circuit. The Cis charged with a supply current which is positively correlated with a load current via the NTr, the SW, the PTr, and the PTr