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.

Date of Patent:
Dec. 03, 2013

Filed:

Jun. 16, 2009
Applicants:

Kiyohito Hara, Osaka, JP;

Koichi Kawano, Tokyo, JP;

Inventors:

Kiyohito Hara, Osaka, JP;

Koichi Kawano, Tokyo, JP;

Assignee:

Ricoh Company, Ltd., Tokyo, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02H 7/00 (2006.01); H02H 9/00 (2006.01); H02H 3/24 (2006.01);
U.S. Cl.
CPC ...
Abstract

In a switching regulator, a low voltage malfunction prevention circuit controls operations of a PWM comparator and a output buffer circuit, such that when a power source voltage is lower than a predetermined value, a switching transistor is forcibly turned off, and when the power source voltage is greater than or equal to the predetermined value, the switching transistor is turned on/off in accordance with pulse signals from the PWM comparator. Furthermore, the low voltage malfunction prevention circuit generates a second reference voltage that is lower than a first reference voltage and that rises quickly in accordance with the rise of the power source voltage. The state of the power source voltage inside an IC is detected by comparing the first reference voltage with the second reference voltage.


Find Patent Forward Citations

Loading…