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:
Oct. 23, 2012
Filed:
Sep. 04, 2008
Junji Nishida, Osaka, JP;
Junji Nishida, Osaka, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A disclosed constant current supply type switching regulator includes a switching element configured to activate a switch operation depending on an input control signal, an inductor configured to be charged with the input voltage in response to the switching element activating the switch operation, a rectification element configured to discharge the inductor in response to the switching element shifting to a cutoff state, a current detection circuit unit configured to generate a current proportional to a current flowing into the switching element and generate and supply a current sense voltage depending on the proportional current and a control circuit unit configured to average the current sense voltage supplied from the current detection circuit unit and perform PWM (Pulse Width Modulation) control on the switching element for supplying a constant current in order to force the averaged voltage to be equal to a first reference voltage. The control circuit unit compares the averaged voltage with the first reference voltage and uses a pulse signal indicative of the comparison to perform the PWM control for supplying the constant current.