Patent ID: 7423857

Claim:
A current detection circuit comprising: a conversion circuit ( 16 ) configured to allow a current to flow therethrough to a power load, and generate an electronic signal passing therethrough; corresponding to the current passing therethrough; and an amplifier circuit ( 17 )configured to include a resistor circuit ( 21 to 23 ) for gain setting, the amplifier circuit amplifying an electric signal, generated by the conversion circuit, by the gain set by the resistor circuit and outputting the amplified electric signal as a current detection signal; wherein: said conversion circuit ( 16 ) and said amplifier circuit ( 17 ) are composed of elements of semiconductor material and formed commonly on a semiconductor substrate ( 100 ); said conversion circuit ( 16 ) and said resistor circuit ( 21 to 23 ) of said amplifier circuit are thermally coupled with each other to transfer a temperature change in said conversion circuit caused by a heat generated by a current flowing through said conversion circuit, so that a gain of said amplifier circuit ( 17 ) is changed in accordance with the temperature change of said conversion circuit ( 16 ) to thereby ensure high accuracy of the output current detection signal even in a case where the temperature change in said conversion circuit causes changes of the electric signal.