Exploring AMR Sensors’ Performance Limits Using an Agile, High-Speed Set–Reset Pulse Generation Circuit

This work explores the performance characteristics of anisotropic magnetoresistance (AMR) sensors when operating with very short set/reset current polarization pulses. AMR sensor's sensitivity, offset, and power consumption are measured and reported using the sequences of set/reset polarization pulses of different durations. In order to perform these measurements, a circuit topology for generating agile current pulses with variable duration down to 40 ns, i.e., about fifty times shorter than similar circuits reported in the literature, was devised. It is demonstrated that AMR sensors maintain their sensitivity and offset even with polarization pulses two orders of magnitude shorter than those recommended in the literature. This allows for the faster magnetic field sampling and the lower power consumption which can significantly broaden the application space of AMR sensors.