A fast switching fast bridge using GaN transistors

This paper presents the design and evaluation of a half bridge based around off-the-shelf gallium nitride power devices and a bespoke printed circuit board. The necessary parasitic evaluation at the design stage was not straightforward due to the incompatibility of the software involved and an intermediate step was required, which is outlined in this work. When the half bridge was subjected to a double pulse test, using a dc link voltage of 450V and an inductor current of 72A, the devices switched ON in 10.4nS and OFF in 3.8nS with minimal overshoot of the drain-source voltage. Layout requirements of fast switching power circuits are also discussed.