Patent ID: 7733186

Claim:
A bias circuit, comprising: a first current source which generates a first current; a second current source which generates a second current having a temperature-to-output current characteristic that an output current characteristic increases or decreases with a change in temperature to intersect with that of the first current; a first current-voltage conversion circuit which converts the first current generated by the first current source to a first voltage; a second current-voltage conversion circuit which has an input terminal and converts a current inputted into the input terminal to a second voltage; a comparison circuit which compares the first voltage and the second voltage and generates a third current according to a result of the comparison; an addition unit which adds the third current to the second current and inputs a resulting current to the input terminal of the second current-voltage conversion circuit; and a voltage-current conversion circuit which converts the second voltage converted by the second current-voltage conversion circuit to a fourth current for bias.