Sensing motor current

摘要

The circuit comprises a driver 109 configured to generate a driving current for a motor; a first current sensor 103 configured to sense the driving current thereby forming a first sensed current; and a second current sensor 104 configured to sense the driving current thereby forming a second sensed current. The second current sensor is more thermally stable than the first current sensor. The two sensed currents may then pass through low-pass filters, into a comparator 108 which compares the two signals below a threshold frequency. The comparator generates a thermal calibration output. A calibrator 106 then adjusts the first sensed current by the thermal calibration output to form a sensed driving current. The circuit is designed to compensate for the thermal drift or shift in temperature sensitive sensors such as Hall elements.