Monolithic GaN-Based Gate Driver With On-Chip Adaptive On-Time Controller and Negative Current Slope Detector to Prevent Shoot-Through

This letter proposes a monolithic gallium nitride (GaN) primary-side controller for a flyback converter, consisting mainly of a negative current slope (NCS) detector to suppress shoot-through problems caused by GaN process defects. Moreover, the proposed adaptive on-time (AOT) controller can adapt to changes in the input voltage and limit the maximum allowable switching frequency to achieve high efficiency. Furthermore, the diode turn-on voltage compensated gate driver also enhances the ability to drive the on-chip 650-V power GaN switch. Therefore, the proposed fully integrated GaN-based chip can improve the efficiency by 2% as the deadtime is reduced from 40 to 7 ns. The proposed gate driver has a peak efficiency of 96.2% and a maximum current of 6 A.