| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetic detection apparatus which suppresses variations in its output while assuring its fail-safe property. SOLUTION: The apparatus is configured such that a detection signal of a magnetic detecting element is converted and processed, and then a digital signal conserved against fluctuation noises in a power supply voltage VDD is converted into an analog signal corresponding to the voltage VDD and processed. In the configuration, a fail detecting circuit 26 comprises: power supply lines 32, 34 to which the voltage VDD is applied; an output line 30 to which the analog signal corresponding to the voltage VDD is input; a charge pump 50 for boosting the voltage VDD and outputting it; a switching circuit 40 which outputs the analog signal from the output line 30, when receiving an output voltage of the charge pump 50 exceeding a switching threshold, and short-circuits the output line 30 and at least one of the power supply lines 32, 34, when receiving an output voltage being equal to or less than the threshold; and a capacitor 62 which is charged when being applied with the voltage VDD, and discharges electricity to the charge pump 50 when applying of the voltage VDD is interrupted. COPYRIGHT: (C)2008,JPO&INPIT
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