Design and Implementation of a Closed Loop AMR Magnetic Sensor
Anastasia Tsalikidou
Abstract
Due to modern needs for taking measurements with higher accuracy, we build a closed-loop anisotropic magnetoresistance sensor. To be more specific, we utilize the high-sensitivity magnetoresistance sensors HMC1001/1002 of Honeywell, the output of which passes through a chopper amplifier. Then, the signal is reinforced by an amplifier, known as instrumentation amplifier. The output of the instrumentation amplifier is fed back to the sensor through a resistor of very high accuracy, which is used for taking measurements by measuring the current through it. By using the closedloop circuit, we achieve operation in the linear region and noise minimization due to chopper amplifier.