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:
Jul. 07, 2009
Filed:
Feb. 27, 2007
Kozo Sakamoto, Hitachinaka, JP;
Kozo Sakamoto, Hitachinaka, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A semiconductor circuit suitable for normally-on switching elements or switching elements low in threshold voltage. A negative power supply is charged by a high-voltage power supply. A high-voltage switch controls the advisability of applying a voltage to a high-voltage terminal. With deducing the power supply to power switching elements, the high-voltage switch is turned off, and even in the case where the voltage of the controlling circuits of the power switching elements is reduced, the power supply capacitors for the controlling circuits are charged by the high-voltage terminal thereby to operate the controlling circuits. Further, a negative power source voltage generating circuit utilizes the energy charged to the capacitors from output terminals. A voltage terminal is inserted between the high-voltage terminal and a reference voltage terminal. The negative power source voltage generating circuit is interposed between the voltage terminal and a plurality of the output terminals.