Dual-NMOS GaN Gate Driver With Active Bootstrap and Infinite-CMTI Level Shifter for Configurable dV/dt and MHz Operation

This letter proposes a novel dual-NMOS gallium-nitride gate driver integrating an active bootstrap (BST) and a high common-mode transient immunity (CMTI) capacitive level shifter (LS). Compared to conventional PMOS-based BST circuits requiring extra LSs, the proposed design utilizes bidirectional NMOS BST switch pairs with dedicated on-off control circuit, providing reliable floating gate voltage with reduced on-chip area. The capacitive LS 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.