A comparison of GMR multilayer and spin-valve sensors for vector field sensing

This paper provides a comparison between GMR multilayer and spin-valve sensors used for magnetic field sensing applications. Both types of sensor considered use a bridge configuration to reduce the effect of thermal drift and are biased to optimize sensitivity and linearity. In comparing the performance of these devices a simple model has been used which has been shown to predict the sensor performance to better that 5% over a wide range of input parameters. It is shown that although spin-valve sensors have a slightly higher sensitivity, linearity, and better signal to noise ratio than GMR multilayer devices, they have a slightly reduced dynamic range and a vastly inferior vector performance. This limits their applications to areas where good vector response is not of importance.