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:
Apr. 19, 2005
Filed:
Apr. 30, 2002
Akira Haraguchi, Kasugai, JP;
Takashi Matsumoto, Kasugai, JP;
Kyuichi Takimoto, Kasugai, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
There are provided a DC/DC converter control circuit and a DC/DC converter system having high degree of freedom of mounting and achieving the following matters: (1) housing a DC/DC converter control circuit in a package miniaturized by reducing the number of terminals; and (2) starting-up a power saving mode in response to an input of an external control signal to a DC/DC converter system. A frequency setting terminal (RT) is connected to a resistance element RT and a switching sectionin series, between the terminal and ground voltage. An external control signal CTL is inputted to the switching sectionWhen an external control signal CTL turns off the switching sectionconnection to the ground voltage is opened and an oscillation driving sectiondoes not operate. Thereby, power saving mode is kept. When the switching sectionis turned on, connection to the ground voltage is closed and the oscillation driving sectionstarts up. Subsequently, a bias control sectionstarts up and bias condition toward the resistance element RT is controlled. Thereby oscillation frequencies approximate to a setting value. Control of power saving mode can be thus carried out without a dedicated terminal for an external control signal CTL.