Comparison of GaN Enhancement Mode Transistor Performance With Integrated and External Driver

Abstract

GaN components allow to reduce power losses as the lower specific on-resistance and higher switching speeds reduce both the conduction and switching loss. However, parasitics in the gate loop cause ringing which endangers the component. To counteract these problems the switching speed is lowered renouncing part of the components superior performance. A possible way to avoid gate loop parasitics and make circuit design less challenging is integrating the driver in the same package with the GaN transistor. In this paper the performance of an integrated driver with enhancement mode GaN half-bridge that is monolithically integrated using IMEC GaN-on-SOI will be tested in a synchronous boost converter setup. Converter efficiency and switching waveforms will be reported together with a comparison to a GaN half-bridge with external drivers. The converter is tested at input voltages up to 50 V and powers up to 100 W. Package temperature measurements are included to estimate the influence of the temperature dependent on-resistance on the results. At the end of the paper, a sensitivity analysis is conducted to quantify the behaviour of the losses in function of different input parameters including a measurement at switching frequencies up to 1MHz.