Patent ID: 7145142

Claim:
A sensor device which detects a physical change amount or chemical change amount, comprising: a sensor array including a plurality of sensors, the sensor array configured to detect the physical change amount or chemical change amount and to output an electrical signal; a sense amplifier circuit configured to amplify the electrical signal to generate an amplified electrical signal; a current transfer circuit configured to include a first stage and a second stage, and to transfer a first current appearing on the first stage on a basis of the amplified electrical signal to the second stage as a second current; a current-to-voltage conversion circuit configured to convert the second current to a first voltage; a first discharging/charging circuit including a capacitor and a first load element connected to the capacitor, said first discharging/charging circuit configured to discharge/charge electric charges from/to the capacitor through the first load element on a basis of the first voltage; and an output circuit configured to output a change in voltage occurring on the capacitor according to discharging/charging of the electric charges.