A low power 16-channel fully integrated GMR-based current sensor

Isolated current and voltage sensors are key components in hybrid or electrical vehicles. For such applications, a low power 16-channel current sensor with 12-bit resolution at 3kS/s per channel and 1.5kV isolation has been developed. It is based on the cointegration of spin-valve Giant MagnetoResistance (GMR) thin-film technology and CMOS technology in one ASIC. Current measurements have been performed with less than 3.5% peak-to-peak non-linearity over a 1 to 20mA current range. The signal BW ranges from DC to 500Hz, and the readout circuit power consumption is only 182μW per channel.