Origin of the Crossfield Effect in AMR Sensors

Crossfield sensitivity is a non-linear effect inherent to AMR sensor. It is caused by the anisotropic character of the sensor. It is important to understand this effect in order to use AMR sensors correctly. The basic model of AMR sensitivity to crossfield is directly derived from the single-domain energy equations. It works for sensors with barber poles and including the sensors forming Wheatstone bridge. One can reduce the effect by changing the sensor geometry, but this also reduces the sensitivity and finally increases the sensor noise. We show other more effective methods of crossfield correction and discuss their properties. The effect can be numerically corrected in multiaxial system, suppressed using flipping or almost annihilated by feedback.