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:
Aug. 07, 2012
Filed:
Oct. 22, 2008
Tatsuya Iwasaki, Kyoto, JP;
Isao Yamamoto, Kyoto, JP;
Tatsuya Iwasaki, Kyoto, JP;
Isao Yamamoto, Kyoto, JP;
Rohm Co., Ltd., , JP;
Abstract
An output voltage monitoring circuit monitors an output voltage of a capacitor charging circuit. A first sample-and-hold circuit samples and holds a voltage of a connection point of a primary coil of a transformer and a switching transistor. A first monitoring comparator compares output of the first sample-and-hold circuit with a predetermined first reference voltage. When the output of the first sample-and-hold circuit exceeds the first reference voltage, a signal processor executes predetermined signal processing. The first sample-and-hold circuit starts a sampling period after a predetermined first time has elapsed after the switching transistor is turned OFF. When a voltage drop across a detection resistor reaches a third reference voltage, the first sample-and-hold circuit ends the sampling period.