| 摘要 |
PROBLEM TO BE SOLVED: To provide a sensor device of small area ensuring a high SN ratio and low noise by reducing the noise components.SOLUTION: A variable resistance sensor RS1A is inserted to the source side of a first input transistor D1A consisting of an N type channel transistor included in a differential pair 11 of a general differential amplifier circuit (so called, operational amplifier), and the current flowing through the differential pair 11 is changed by using a phenomenon that the value of resistance of the variable resistance sensor changes when sensing a physical quantity, thus changing the output signal of the operational amplifier. Consequently, an output signal depending on the magnitude of the physical quantity, and the change in the value of resistance of the variable resistance sensor RS is outputted as the output signal of the operational amplifier.SELECTED DRAWING: Figure 1 |
