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. 28, 2007
Filed:
Oct. 13, 2005
Hirohisa Warita, Kitakatsuragi-gun, JP;
Atsushi Kanamori, Ikoma-gun, JP;
Katsumi Inaba, Tondabayashi, JP;
Tsutomu Satoh, Yamatotakada, JP;
Hirohisa Warita, Kitakatsuragi-gun, JP;
Atsushi Kanamori, Ikoma-gun, JP;
Katsumi Inaba, Tondabayashi, JP;
Tsutomu Satoh, Yamatotakada, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
In a switching power supply circuit, completion of discharging of a capacitance provided in a soft-start circuit requires a period longer than a cycle with which an activating/deactivating portion switches switching control operation of a driving portion (which performs switching control to turn on/off a switching device provided in a stepping-up DC-DC converter) between an activated state and a deactivated state. Moreover, the soft-start circuit is prevented from performing soft-start operation until discharging of the capacitance is completed. Furthermore, the activating/deactivating portion prevents the switching control operation of the driving portion from being switched from the deactivated state to the activated state from a time point that constant voltage feeding operation of a constant voltage portion (which feeds, to a comparing portion that sends an output signal to the driving portion, a constant voltage as the drive voltage) is switched from the deactivated state to the activated state until a predetermined period elapses.