Current detection apparatus

A current detection apparatus adopting a semiconductor switch disposed at an electrical conduction path to a load to detect a load current flowing through the load, the current detection apparatus comprising:

• a voltage detector including an output terminal configured to output a detected voltage indicating a voltage generated across terminals of the semiconductor switch according to the load current;
• a candidate voltage generator including a plurality of correction resistors connected in series and connecting the output terminal and a ground, the candidate voltage generator configured to generate a plurality of candidate voltages at respective sections across the corresponding correction resistors, the plurality of candidate voltages respectively calculated by multiplying a plurality of corrected magnification scales to the detected voltage;
• a temperature detector configured to detect a temperature of the semiconductor switch as a measured temperature;
• and
• a correction voltage selector including a plurality of switches respectively connected to the correction resistors, and configured to select one of the plurality of candidate voltages as a corrected voltage by turning on only a corresponding one of the switches and turning off all of the remaining switches, the one of the plurality of candidate voltages weighted with corresponding one of the plurality of corrected magnification scales corresponding to an on-resistance of the semiconductor switch at the measured temperature, the corrected voltage indicating a corrected current value with correction of the load current according to the measured temperature,
• wherein each of the corrected magnification scales is a magnitude acquired through dividing a first value by a second value,
• wherein the first value is a total resistance of one or more of the correction resistors connected in series from a position at a corresponding one of the respective sections to a ground side, and
• wherein the second value is a total resistance of all of the correction resistors connected in series from the output terminal to the ground side.