Linear Spin-Valve Bridge Sensing Devices

Abstract

Spin-valves are applied in a variety of devices including magnetic sensors and isolators. The linear spin-valve sensing element is configured as a Wheatstone bridge consisting of four sensing resistors. The sensing devices are characterized by three parameters: the sensing field range, sensitivity and linearity. The devices using linear spin-valve sensing elements exhibit excellent performance. A Linear magnetic field sensor constructed of a bridge with 4 /spl mu/m wide line serpentine resistors shows a sensitivity of 1.6 mV/V-Oe in the operation range of -5 Oe to 5 Oe. An analog magnetic isolator constructed of a bridge with 4 /spl mu/m wide line serpentine resistors exhibits superior performance with a sensitivity of 1.27 mV/V-mA and a linearity error less than 0.05%.