A Wide-Frequency-Range GaN Half-Bridge Driver with Reconfigurable High-Voltage Charge Sharing Path

To address the challenges of narrow operating frequency range and insufficient high-side supply rail voltage at high frequencies in GaN half-bridge drivers, this paper proposes a driver capable of operating at 1 ∼ 10 MHz switching frequency with a high-side driving voltage of 4.99 V. The proposed driver incorporates two novel techniques: reconfigurable charge sharing path (RCSP) and high-voltage charge sharing. By modulating the resistance of the charge sharing path through RCSP, the charging rate of the sharing path can be regulated, thereby enabling the driver to operate over a wider switching frequency range. The high-voltage charge sharing technique enhances the charging rate of the bootstrap path, thereby ensuring sufficient high-side driving voltage even at elevated switching frequencies. This design was fabricated and verified using a 0.18 μm BCD process. It achieves a high-side driving voltage ranging from 4.02 V to 4.99 V at switching frequencies of 1 ∼ 10 MHz, demonstrating a 28.8% enhancement in the high-side driving voltage at 10 MHz.