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. 12, 2005
Filed:
Nov. 20, 2003
Takuya Okubo, Kyoto, JP;
Koh Takemura, Kyoto, JP;
Takuya Okubo, Kyoto, JP;
Koh Takemura, Kyoto, JP;
Rohm Co., Ltd., Kyoto, JP;
Abstract
According to the conventional stabilized DC power supply device, there is a possibility that the output transistor breaks down by heat when the input voltage fluctuates. To cope with this, the stabilized DC power supply device embodying the invention is so configured as to comprise an output transistor for converting an input voltage to an output voltage and feeding out the output voltage, a control circuit for controlling the output transistor so as to maintain a value of the output voltage constant, a current detection circuit for detecting an output current of the output transistor, a voltage detection circuit for detecting a voltage appearing between an input side and an output side of the output transistor, a multiplying circuit for multiplying an output of the current detection circuit and an output of the voltage detection circuit together, and a protection circuit for restricting a wattage power of the output transistor according to an output of the multiplying circuit.