| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a capacitive sensor device that detects the size of the physical quantity of a detection target on the basis of capacitance by stably operating with a simple circuit configuration.SOLUTION: A capacitive sensor device of the present invention includes: a capacitive sensor element that has a sensor capacitance part having capacitance according to the size of the physical quantity of a detection target, and a reference capacitance part having reference capacitance; an operational amplifier that has a non-inverting input terminal to which a reference potential is supplied; a capacitor that is connected between an output terminal and an inverting input terminal of the operational amplifier; and a switch circuit that switches the connection state of the capacitive sensor element so that in a first integration period, the sensor capacitance part and reference capacitance part are connected in parallel between the output terminal and the inverting input terminal of the operational amplifier and in a second integration period, the reference capacitance part is connected between the output terminal and the inverting input terminal of the operational amplifier.</p> |
