Investigation on Non-invasive Current Mismatch Measurement in Paralleled GaN HEMTs

On the recent advancements in current sensor field, single chip contactless current sensors enable the end users to efficiently monitor the switching current in modern power electronics systems. This work further investigates a novel low-cost measurement technique based on Magnetoresistive (MR) sensors. The process uses a single current sensing unit, measuring the current mismatch between the two parallel Gallium Nitride (GaN) MOSFETs, which would be used for prognostic and protection purposes. The magnetic field distribution analysis of GaN devices in switching converter is investigated using FEA simulations, in order to optimize the MR sensor location. The experimental results verify the sensitivity and linearity of the sensing unit up to 20 A of current mismatch.