A 12-MHz GaN-Based DC-DC Buck Converter Featuring Dual Reverse Conduction Controllers

초록

This brief presents a 12-MHz 30V-to-12V GaN-based DC-DC buck converter incorporating a high-efficiency gate driver IC with dual (high-side and low-side) reverse conduction controllers (RCCs). The proposed dual RCCs dynamically minimize dead time and reverse conduction losses in the half-bridge GaN power stage. An active bootstrap circuit is also integrated to suppress bootstrap capacitor overcharging during reverse conduction. In addition, the gate driver IC includes a feedback control block and integrates nearly all essential building blocks (such as a PWM generator, a bias generator, and protection circuits) eliminating the need for external controllers. Fabricated in a 180-nm 30-V BCD process, the proposed gate driver IC occupies an active area of only 0.91 mm². Measurement results show that the proposed buck converter achieves reverse conduction times of only 3.04 ns (VSW rising edge) and 3.5 ns (VSW falling edge), resulting in a 6.1% improvement in conversion efficiency, achieving a peak power efficiency of 85.75%.

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