Texas Instruments Incorporated
System for continuous calibration of hall sensors

Abstract:

A system comprises a calibration current generator, which provides a calibration current to a first and a second Hall channel, and a bias current generator, which determines a difference between a calibration signal from the Hall channels and a threshold and adjusts a biasing current for the Hall channels based on the difference. In some embodiments, the bias current generator comprises a subtractor coupled to an ADC and a controller coupled between the ADC and a DAC. The subtractor obtains a first and a second signal from the first and second Hall channels, respectively, and subtracts the first from the second to obtain the calibration signal. The controller determines the difference between a sampled signal from the ADC and the threshold and an adjustment to the biasing current based on the difference. The DAC adjusts the biasing current based on a control signal from the controller indicating the adjustment.