An Integrated and Galvanically Isolated DC-to-15.3 MHz Hybrid Current Sensor

A wide-bandwidth galvanically isolated current sensor in a 180 nm CMOS technology is presented. It combines two sensing principles for the contactless and lossless current measurement in power electronic applications. A dedicated vertical Hall sensor (low frequencies) and an integrated helix-shaped Rogowski coil (high frequencies) enable to measure currents in any power line under the chip from DC up to 15.3 MHz, which exceeds prior art by 5x. Both sensing concepts are fully integrated on one microchip without the need for any kind of magnetics or post-processing. The wide bandwidth results in fast transient properties, verified by an IGBT double pulse measurement of current pulses with an amplitude of 60 A and slew rates up to 1 kA/μs. A sensitivity of 3.1 mV/A is achieved.