A high-speed level shifter with adaptive positive dV/dt noise blanker for GaN-based buck converters

—Level shifters play a crucial role in high-frequency switched-mode power supplies (SMPS). In GaN-based SMPS systems where switching nodes experience rapid transitions, two critical parameters determine level shifter performance: propagation delay and common-mode transient immunity (CMTI). While conventional approaches to improve CMTI typically employ noise filters, these solutions often introduce substantial propagation delays. To address this limitation, we present a high-speed level shifter design featuring an adaptive positive dv/dt noise blanker. This solution operates based on the converter's working principle, effectively blocking noise paths during fast switching transitions without compromising delay performance. Implemented in 0.18 μm Bipolar-CMOS-DMOS (BCD) process, the simulation and measurement results of the proposed design show a delay of 0.937 ns and 400 V/ns of dV/dt CMTI at floating voltage 50 V.