Low-Voltage GaN FET in High Power Density Half-Bridge LED Driver

In the paper, a half-bridge GaN FETs-based converter for a LED driver circuit is investigated. The reduced size of the GaN devices allows reaching high power density compared with the pure silicon devices. The main technology and electrical characteristics are recalled to demonstrate the advantageous features in the DC-DC applications such as of Synchronous Buck Converter. The dead time reduction, the parasitic capacitors, and stray inductances impact the switching operation is described. Furthermore, the control approach and the GaN FETs related issues are investigated. Finally, the switching evaluation of an SBC with an output power of 120W at 1MHz of switching frequency is carried out highlighting the thermal behavior.