Sensor device

摘要

Provided is a sensor device capable of removing the influence of each offset voltage of a sensor element, a differential amplifier, and an amplifier of the sensor device, to thereby detect a physical quantity with high precision. The sensor device includes: a switch circuit, which is connected to a first terminal pair and a second terminal pair of the sensor element, for controlling switching of the terminal pairs and outputting detection voltages; a differential amplifier, which includes a first input terminal and a second input terminal connected to a first output terminal and a second output terminal of the switch circuit, respectively, for outputting a result obtained by amplifying a difference of the detection voltages; an amplifier including at least two differential input pairs, one of which inputs the differential signal output from the differential amplifier, and at least one of which inputs a reference signal corresponding to a physical quantity to be detected; and a detection voltage setting circuit for outputting the reference signal to the amplifier.

主权项

1. A sensor device for generating a logic output in accordance with intensity of a physical quantity applied to a sensor element,
the sensor device comprising: a switch circuit, which is connected to a first terminal pair and a second terminal pair of the sensor element, for controlling switching between a terminal pair supplied with power and a terminal pair for outputting a detection voltage corresponding to the intensity of the physical quantity,
the switch circuit comprising a first output terminal for outputting the detection voltage and a second output terminal for outputting the detection voltage; a differential amplifier comprising: a first input terminal and a second input terminal, which are connected to the first output terminal and the second output terminal of the switch circuit, respectively; and a first output terminal and a second output terminal for outputting a result of differentially amplifying the detection voltage; an amplifier comprising a first input terminal, a second input terminal, a third input terminal, a fourth input terminal, and an output terminal,
the first input terminal of the amplifier being connected to the output terminal of the amplifier via a first switch,the first input terminal of the amplifier being connected to the first output terminal of the differential amplifier via a first capacitor,the second input terminal of the amplifier being connected to the second output terminal of the differential amplifier; and a detection voltage setting circuit for outputting different voltages to the third input terminal and the fourth input terminal of the amplifier.