A High-Efficient GaN Driver With Hybrid Adaptive Dead-Time Control and Peak Delay Control for Synchronous Buck Converter

This paper presents a GaN driver with a switching frequency (fSW) ranging from 1 MHz to 10 MHz for reliable and efficient power conversion. A hybrid adaptive dead-time control technique is proposed. The dead time is first coarsely adjusted by a digital delay control to achieve a target resolution, and then further fine-tuned by an analog delay control. This approach resolves the inherent trade-off between transition time and resolution in dead-time adjustment. Additionally, to mitigate the minimum on-time limitation of the input signal caused by the level shifter's high-frequency operation, an adaptive blanking level shifter is developed. To verify the proposed design, a synchronous buck converter was implemented in a 0.18-μm BCD process. The hybrid adaptive dead-time control achieved a transition time of one cycle with dead time of 0.191 ns to 0.360 ns at 1 MHz and dead time of 0.274 ns to 0.291 ns at 10 MHz fSW. When tested with voltage conversion from 12 V to 6 V, the peak efficiencies reached 96.60% and 93.56% at 1 MHz and 10 MHz, respectively.