Analog behavioral modeling of magnetoresistive sensors

A behavioral circuit model of anisotropic magneto resistance (AMR) sensors that operates by modulating the drive bias on soft-adjacent-layer is developed. The non-linear extrinsic behavior of the sensor is modeled by constructing a two-dimensional (2D) polynomial at DC level for the variation of the sensor drive current controlled by the self bias of the sensor and magnetic field bias. Analog Behavioral Model is used to implement the model in SPICE. The simulation of second harmonic (2f) sensitivity signal and its comparison to the experimental data in a bridge configuration is presented. The comparison made with the experimental data permits the accurate prediction of 2f measurement for AMR sensors.