| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power supply voltage controller for properly preventing the supply of an abnormal voltage to a load and its control method when the open failure of a terminal for feedback is generated. <P>SOLUTION: When a VCC1 terminal voltage decreases, and falls below an allowable voltage range due to opening of a terminal VCC1 for feedback, a first AND circuit 24 of an abnormality determination circuit 18 turns on a transistor Tr<SB>4</SB>to turn off a transistor Tr<SB>2</SB>, and turns off a transistor Tr<SB>1</SB>for output to stop an output voltage. Also, when a VCC2 terminal voltage decreases, and falls below an allowable voltage range due to opening of a terminal VCC2 for voltage monitor, it turns on a transistor Tr<SB>5</SB>, and turns off the transistor Tr<SB>2</SB>, and turns off the transistor Tr<SB>1</SB>to stop the output voltage. Thus, it is possible to stop the supply of a power supply voltage to a load R<SB>L</SB>, and to suppress the abnormal increase in a load supply voltage. Therefore, it is possible to suppress the abnormal increase in the load supply voltage by avoiding voltage variation which may occur in a conventional technology using a clamp circuit including a Zener diode or the like. <P>COPYRIGHT: (C)2007,JPO&INPIT |
