Driving GaN HEMT High-Voltage Half-Bridge with a Single-Channel Non-Isolated Gate Driver with Truly Differential Inputs

This paper describes the functional principle of a non-isolated gate driver with truly differential inputs (TDI) and the benefits of its application in GaN HEMT high-voltage resonant half-bridge DC-DC converters (LLC). This innovative gate driver is able to overcome the driving issues associated with DC ground-shift or AC noise between controller and driver IC ground potentials, enabling its application even in high-side driving as a replacement of isolated gate drivers. Test results obtained in a GaN HEMT based 600 W / 400 V / 300 kHz half-bridge resonant converter are provided.