TMR Magnetic Sensor Array Module for Detecting Leakage Current in Lithium-ion Batteries

Abstract

A TMR magnetic sensor array module with multi-channel synchronous detection ICs is proposed for detecting the extremely low leakage current in lithium-ion batteries. The sensor array consists of a multiple-element, highly sensitive, self-biased TMR magnetic sensor GIGS^® using an SmCo thin-film magnet. The 10ch demonstration module was successfully detected a low current of less than 3.6 mA in a laminated lithium-ion battery. The module noise in an RF shielded room was about 44 nT/√Hz at 100 Hz.