P5.4 - Novel Dynamic Technique Reducing the Offset Voltage in a Hall Effect Sensor

SENSOR+TEST Conferences 2011
2011-06-07 - 2011-06-09
Proceedings SENSOR 2011
P5 - Magnetic
V. Petoussis - Universität Würzburg (Germany), P. Dimitropoulos, G. Stamoulis, E. Houstis - University of Thessaly, Volos (Greece)
780 - 785


Silicon Hall plates show an offset of a few millitesla. A large portion of this offset is caused by mechanical stress in the device. The offset can be reduced when the spinningcurrent principle is applied. In this work we present a model and numerical analysis of a new Hall effect sensor which using a novel offset reduction method. We call it “Wheel Hall Senor”.The device exploits the signals attributed to Hall voltage, Hall current and geometric MR effect. As a result the Device is equivalent to an “ideal” voltage or current Hall sensor with geometrical factor of one (GH = 1). Moreover it provides for high-speed spinning, given that the voltage distribution changes moderately between different phases. This is equivalent to minimum charge injection that 0 in turn – allows spinning frequency increase.The device senses all 3 filed dimensions, namely the flux-density of BZ is proportional to the DC component of the output signal, whereas the BX and BY components are proportional to the first harmonic of the output signal. Finally the device can be made in a way to reuse the current, if integrated in a BiCMOS technology providing for matched JFETs. Furthermore we calculate the function which governs the changes in the electric field inside the new Hall effect sensor in presence of magnetic field.This function help us to control in MatLab environment the equipotential lines and to monitor the changes when biasing conditions are change. The combination of his pioneering form and the elaborate sequence of using the dynamic spinning current technique, leads to satisfactory results of produced Hall voltage with small noise in a presence of external magnetic field.