| 摘要 |
In a capacitive physical quantity sensor, a C-V converter converts a variation in a capacitance between a movable electrode and a fixed electrode into a voltage to output the converted voltage in a first operating mode. The C-V converter also outputs a constant voltage in a second operating mode. An amplifier amplifies the converted voltage to output a first voltage, and amplifies the constant voltage to output a second voltage. A first sample and hold circuit operates in the first operating mode to sample and hold the first voltage. A second sample and hold circuit operates in the second operating mode to sample and hold the second voltage. A first differential amplifier obtains a difference voltage between the first voltage held by the first sample and hold circuit and the second voltage held by the second sample and hold circuit.
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