| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply voltage detection circuit capable of preventing malfunctions of a system by having stable power supply voltage detection signals even when a power supply voltage is lowered to a voltage lower than a prescribed voltage. SOLUTION: The power supply voltage detection circuit is provided with a first power supply voltage detection circuit; a second power supply voltage detection circuit; and a logic circuit. In the first power supply voltage detection circuit, its output signals are inverted when a power supply voltage is lowered to a first voltage, and its output signals are inverted at least once or more in a voltage region lower than a second voltage lower than the first voltage when the power supply voltage is further lowered. In the second power supply voltage detection circuit, its output signals are inverted only once in a voltage region lower than the first voltage and higher than the second voltage when the power supply voltage is lowered. The logic circuit performs logical operations on output signals of the first power supply voltage detection circuit and the output signals of the second power supply voltage detection circuit and outputs a detection signal indicating that the power supply voltage is a voltage lower than the first voltage or not. COPYRIGHT: (C)2006,JPO&NCIPI
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