Patent ID: 8039797

Claim:
A semiconductor device comprising: a sensor configuration which includes a light receiving portion for converting incident photons into heat and a sensing portion integrated with the light receiving portion and having a resistance varying according to the converted heat; and a sensing circuit which includes: a first current mirror in which a current flows corresponding to a current flowing in the sensing portion; a first common mode current providing portion which outputs a first common mode current having a size corresponding to a multiple of a value of a current which is flowing in the sensing portion when there is no incident light; a first current subtraction portion which outputs a subtraction current by subtracting an output from the first common mode current providing portion from an output from the first current mirror; a second current mirror in which a current flows corresponding to an output from the first current subtraction portion, a second common mode current providing portion which outputs a second common mode current having a size corresponding to the first common mode current from the first common mode current providing portion; and a second current subtraction portion which outputs a subtraction current by subtracting the second common mode current from the second common mode current providing portion and an output from the second current mirror.