Patent ID: 8576001

Claim:
An offset compensation apparatus for a magnetic detection circuit, the apparatus comprising: an amplifying unit amplifying an output voltage in a first detection state output from a Hall element and an output voltage in a second detection state output from the Hall element, and outputting the amplified voltages; an offset detection unit receiving the output voltage in the first detection state and the output voltage in the second detection state output from the amplifying unit, detecting an offset, and outputting the detected offset; a comparison unit determining whether or not the offset output from the offset detection unit is greater than a pre-set positive reference value or smaller than a pre-set negative reference value, and outputting a determination result; a counter unit increasing a first count value by 1 at a time when the offset is greater than the pre-set positive reference value and increasing a second count value by 1 at a time when the offset is smaller than the pre-set negative reference value based on the determination result output from the comparison unit; and a current supply unit providing a current proportional to the first count value from the counter unit to the amplifying unit to reduce an output voltage, and allowing a current proportional to the second count value from the counter unit to flow from the amplifying unit to increase the output voltage.