PCB Design Impact on GaN-Based Converter Operation

Gallium Nitride (GaN) transistors are well known for use in different power converters like inverters, buck and boost converters, active rectifiers. Superior parameters of GaN semiconductor devices enable the increase of energy efficiency and switching frequency, thus drastically reducing the volume of such converters. Improper Printed Circuit Board (PCB) design can greatly negate the good properties of GaN switches. This paper studies the effects of parasitic elements PCB switching loops along with thermal conductivity. To compare different PCB layout types, three synchronous boost converters with GaN switches were designed, built and tested. Converter layouts were as follows: simple 2-layer design with bottom-cooled transistors; more elaborate interleaving 4-layer PCB with the same transistors; 4-layer PCB with top-cooled transistors. The analysis of the test parameters is likely to support the PCB designers in their effort to create parametrically and economically optimized PCBs for various GaN-based applications.