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:
Dec. 28, 2010
Filed:
Sep. 12, 2008
Shinichiro Yamada, Ikeda, JP;
Shinichiro Yamada, Ikeda, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A switching regulator switches according to an input signal and performs PWM control with a PWM pulse signal. The switching regulator includes a pulse width limiting circuit that includes a reference current source, a constant current source, a capacitor, an inverting block including a first switch circuit to supply a constant current to the capacitor and a second switch circuit to discharge a voltage across the capacitor to a ground, a determination circuit to determine whether the voltage across the capacitor becomes a given value or greater, and a limiting circuit to limit a pulse width of the PWM pulse signal. The inverting block further includes either a third switch circuit configured to pass the given constant current or a switching control circuit configured to cause the first and second switch circuits to pass the given constant current regardless of the PWM pulse signal.