Analysis and Optimization of GMR Based Current Sensors with Identical Pinning Orientation

Abstract

A scheming methodology of Giant Magnetoresistance (GMR) based current sensors is proposed in this paper, in order to minimize the nonlinearity and offset voltage caused by layout design without affecting the sensitivity. Based on the theoretical analysis of the current sensors with identical pinning orientation, several proper schemes of design are presented and discussed. Then, the finite-element method (FEM) is applied to model the 2D and 3D magnetic distribution of the sensors. The distance between two current paths, the location of the y-direction current path are well arranged to eliminate the interferences of the undesired magnetic resources. The relationships among width and thickness of the sensing element, electrical current and distance between the current path and the sensing element are also quantified to guide the dimensional design of the current sensor.