Dual-NMOS GaN Gate Driver With Active Bootstrap and Infinite-CMTI Level Shifter for Configurable d<i>V</i>/<i>dt</i> and MHz Operation

This letter proposes a novel dual-NMOS GaN gate driver integrating an active bootstrap and a high common-mode transient immunity (CMTI) capacitive level shifter. Compared to conventional PMOS-based bootstrap circuits requiring extra level shifters, the proposed design utilizes bidirectional NMOS bootstrap switch pairs with dedicated on-off control circuit, providing reliable floating gate voltage with reduced on-chip area. The capacitive level shifter achieves theoretically infinite CMTI by isolating differential-mode logic signals from common-mode noise through current-mirror-based edge-detection and noise isolation. Furthermore, the dual-NMOS high-side buffer enables continuously adjustable dV/dt via adaptive Miller plateau detection and configurable gate charging currents, reducing switching losses and voltage spikes versus fixed gate-resistor drivers. Experimental results demonstrate a peak efficiency of 91.8% in a 12-to-1.8 V conversion and 4.6% efficiency improvement under 48 V input and 2 MHz switching frequency, validating its potential for high-frequency, high-density power applications such as automotive DC-DC converters.