Effective Use of Miniature, Multi-Point, Field-Based Current Sensors without Magnetic Cores

A methodology for decoupling cross-coupled fields in compact, integrated current sensor arrays is presented. The compactness of the current sensor array elements is made possible by using highly sensitive field detectors based upon giant magnetoresistive (GMR) technology, which offers galvanic isolation, small size (~mm²) and high bandwidth (>1 MHz). By using known geometric relations between the conductor geometries and locations of the field detectors, cross-coupled magnetic field signals can be used to extract necessary current signals, as well as separate unknown disturbance fields. This methodology can also be used to simplify the magnetic biasing requirements of GMR field detectors, including decoupling of the temperature dependence of the biasing magnet. Moreover, the methodology also can be extended to estimate the temperature of the magnet to provide an extra temperature signal for thermal management algorithms.