Thermal behaviour of CMOS Hall sensors for different operating modes

New results obtained with CMOS Hall sensors are presented. The dependence of the sensitivity on temperature has been investigated for constant-current and constant-voltage operation modes. The current-related sensitivity varies with a very low value of 0.03 percent/degree C in the constant-voltage mode. A new NMOS Hall sensor with eight contacts enables the spinning-current technique to be used for offset reduction. The averaged offset values of all eight possible current directions in this sensor exhibit an offset suppression by a factor up to 2000. This leads to a magnetic-field offset of the spinning-current sensor of less than +/-200 myT for a wide temperature range.