Continuous Current Sensing GaN Half-Bridge ICs

This work presents two GaN-integrated approaches for continuous inductor current sensing in half-bridge power converter circuits. The first approach utilizes an integrated drain current mirror on the low-side and a source current mirror on the high-side, combined via a single transimpedance amplifier referenced to the switch node. The second method employs integrated shunt resistors on the low-side drain and high-side source, enabling continuous current sensing through analog summation. Both techniques are experimentally validated and shown to provide accurate, high-bandwidth current signals suitable for control and protection. Additionally, the paper offers a comparative review of state-of-the-art GaN current sensing technologies. Continuous current sensing in GaN half-bridges simplifies the interface and circuitry to external controllers, while enabling effective control and robust protection of power ICs and converters.