In-Plane Sensitive Magnetoresistors as a Hall Device

Abstract

A novel coupling of a pair of identical two-contact (2C) magnetoresistors transformed into an in-plane sensitive Hall device is presented. The ohmic contacts are cross-linked, also adding a load resistor bridge, providing for constant current mode of operation and eliminating the inevitable parasitic offset. This silicon configuration, apart from its simplified layout, has linear and odd output voltage as a function of the magnetic field and current. The quadratic and even magnetoresistance in the two parts of this innovative device is completely compensated, which ensures high measurement accuracy alongside with identification of the magnetic field polarity. The experimental prototypes feature sensitivity of 110 V/AT. The mean lowest detected magnetic induction B at supply current of 3 mA over frequency range f ≤ 100 Hz at a signal-to-noise ratio equal to unity is Bmin ≈ 10 μT. Тhe high performance and the complete electrical, temperature and technological matching of the parts of this unusual Hall device make it very promising for many practical applications.

Keywords

• in-plane sensitive magnetic-field configurations
• magnetoresistors
• silicon Hall effect device