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:
Jun. 30, 2009
Filed:
May. 28, 2004
Ikuo Fukami, Kanagawa, JP;
Ikuo Fukami, Kanagawa, JP;
NEC Electronics Corporation, Kawasaki, Kanagawa, JP;
Abstract
In a power supply control apparatus for controlling supplying of power from a battery to a load, a power supply switch circuit chip is connected to the load, to turn ON and OFF a connection between the battery and the load. A control circuit chip is powered by the battery to control the power supply switch circuit chip. The control circuit chip is constructed by an internal circuit for controlling the power supply switch circuit chip, a parasitic diode connected in parallel to the internal circuit, and a depletion type MOS transistor connected in series to the internal circuit. Diode characteristics of the parasitic diode and the depletion type MOS transistor are opposite to each other with respect to the battery. That is, in a forward-connected battery state, the parasitic diode and the depletion type MOS transistor are reverse-biased and forward-biased, respectively. In a reverse-connected battery state, the parasitic diode and the depletion type MOS transistor are forward-biased and reverse-biased, respectively.