Study and Noise Analysis of a Linearizing Front-End Circuit for GMR Sensors
Sagnik Dutta, Tapabrata Sen, C. S. Anoop · 2019
This paper reports an extensive noise analysis of a simple linearizing interface circuit for Giant Magneto-Resistance (GMR) sensors. Commercially available GMR sensors have a non-linear relationship with respect to magnetic fields. Yet, they are required to be used in many applications where a linear input-output characteristics is needed. This calls for the development of high performing linearizing circuits for GMR sensors. This paper extends the work, presented in one of the research papers, on linearizing circuits for GMR. The reported circuit is simple and provides excellent linearity. However, the noise of the circuit elements can affect the performance. Hence, this necessitates for the noise analysis of such a front-end to determine the subtle parameters like resolution of the circuit. Noise formulation using mathematical studies has been carried out and performance has been evaluated. Simulation studies were also conducted to validate the mathematical formulation. Results from simulation were found to be in agreement with mathematically obtained results. Further, a hardware model of the circuit was developed and tested. The results obtained from the experimental setup was found to be in the same order as the previous results. A compensation method to reduce noise and its effect on dynamic performance of the circuits has also been briefed in the paper.