| 摘要 |
PROBLEM TO BE SOLVED: To reduce the occurrence of the erroneous determination of self-diagnosis in which a defective acceleration sensor is determined as a good one under affection of noise heretofore, without using an amplification factor switching circuit which largely changes the amplification factor in place of the amplifier circuit of the signal process circuit. SOLUTION: The booster circuit in the self-diagnostic circuit side of the acceleration sensor includes a voltage reference circuit, an impressed voltage regulation circuit, and a booster circuit. The voltage reference circuit includes the load 140 for voltage detection, the constant current circuit 150 for making flow the constant current to the load 140. Furthermore, the temperature characteristics of the reference voltage Vref output from the voltage reference circuit is set up such that the temperature characteristics of the output voltage of the voltage booster circuit impressed on the self-diagnostic electrode at the self-diagnostic time cancels the temperature characteristics of the signal process circuit of the sensor chip. COPYRIGHT: (C)2006,JPO&NCIPI
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