| 摘要 |
PROBLEM TO BE SOLVED: To provide a capacitive type physical quantity sensor capable of amplifying a sensor output with a low noise. SOLUTION: A prestage amplifying circuit 23 is arranged on a subsequent stage of a C-V conversion circuit 21. Hereby, an output voltage from the C-V conversion circuit 21 is amplified by the prestage amplifying circuit 23, to thereby heighten sensitivity of a capacitive type acceleration sensor. Since the prestage amplifying circuit 23 is arranged in the preceding stage of a differential amplifying circuit 24, even if a noise carried by the output from the C-V conversion circuit 21 is amplified by the prestage amplifying circuit 23, a noise component can be removed by a sample hold circuit 24a provided in the differential amplifying circuit 24. The capacitive type acceleration sensor capable of amplifying the sensor output with a low noise can be acquired by this constitution. COPYRIGHT: (C)2006,JPO&NCIPI
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