Magnetoresistor linear position sensor for automotive applications

Magnetoresistors (MRs) are semiconductor devices that exhibit a change in resistance in the presence of magnetic field. Recently sensors utilizing MR devices are gaining more interest for a variety of automotive applications. This paper presents magnetic design optimization of a magnetoresistor linear position sensor. The output of the sensor is an analog voltage proportional to the linear movement of a sensed ferromagnetic target. The sensor magnetic circuit was optimized for maximum sensitivity and linearity using two-dimensional finite element analysis. The sensor final design was built and tested. A comparison between the measured and calculated performance to verify the model indicated good agreement