Bridging the gap between AMR, GMR, and Hall magnetic sensors

Abstract

By integrating a magnetic flux concentrator (IMC) at the surface of a Hall magnetic sensor, we can dramatically improve its characteristics. Here we compare the performance of a new IMC Hall sensor ASIC with the performance of traditional magnetic field sensors, such as AMR, GMR, and conventional Hall sensor ASICs. We find that the detectivities of AMRs and GMRs for AC magnetic fields are much better than those of Hall ASICs; for low-frequency fields, the performance gap is smaller; but for DC fields, the resolution of the IMC Hall ASIC is much better than that of GMRs and approaches the resolution of a nonswitched AMR. Also according other parameters, the IMC Hall ASIC is positioned in the gap between AMRs, GMRs, and the conventional Hall ASIC magnetic field sensors.