A hall sensor microsystem for current measurement used in watt-hour meter

A Hall sensor is widely used in automotive and industrial applications. However, the design of Hall sensor on silicon faces the challenges of temperature drifting and DC offset. This paper presents a Hall sensor microsystem with continuous sensitivity auto-calibration and offset voltage compensation, which do not disturb the sensor's normal operation. It has been shown that the offset of the Hall sensor output voltage has been minimized to be less than 5mV. Moreover, the system sensitivity can be fully programmed, between 60V/T and 200V/T. The circuits with on-chip Hall plates have been implemented using a 3.3V 0.35μm CMOS process with a 12.25mm² area.