Abstract:A lowcost noninvasive coreless current monitoring microsystem is proposed for production and living power safety, which is based on a single monaxial tunneling magnetoresistance sensor. The principle and key points for measuring cable current with the magnetoresistance sensor are demonstrated. A detachable package with limit mechanism is designedto ensurethe reliabilityofthemeasurementtransferrelationship withthe compact structureandconvenientmeasurement. Itdoesnot needthetraditional redundant magneticcoreor multi sensors. The high integration and low power microsystem hardware are realized. The accurate measurement and calibration algorithms are achieved by software. A test environment is built according to the city power specification. Test results show good linearity and consistency of the developed current monitoring microsystem. A maximum error of 15% in the 0~8 A range is verified within the national standard of 05 level. It also has good longtime stability and antiinterference ability to adjacent line, which shows the developed microsystem suitable for most residential power monitoring scenarios.