Design and Implementation of an Integrated Current Sensor for a Gallium Nitride Half-Bridge

Current measurement is a critical task for the protection of power devices. This work presents the design and implementation of a printed circuit board integrated, inductive current sensor for short circuit protection of a Gallium Nitride transistor half-bridge. The requirements for the sensor were derived based on the requirements for short circuit detection of fast Gallium Nitride semiconductors. The sensor geometry was optimized numerically based on the stray magnetic field of the commutation loop. The fabricated sensor was measured in the frequency and time domains, showing very good agreement with the simulated results and also in comparison with a coaxial shunt measurement.