—In this paper, a level shifter with high dV/dt immunity and high speed is presented for GaN drivers. During dV/dt transitions of floating power supply, a resistor-based decoupling technique (RDT) is applied for the level shifter to completely eliminates the interference of dV/dt-induced noise on the output logic. A cross-controlled noise blanker (CCNB) is also added to further improve the reliability of output logic. The dV/dt immunity of the level shifter is significantly improved. Moreover, a short pulse charging circuit helps speed up response speed during level shifting. This circuit has been fabricated in a 0.35 μm 100 V HV CMOS process and occupies an active chip area of 0.055 mm2. Experimental results confirm that the proposed level shifter works at 5 MHz, achieving 80V/ns dV/dt immunity with a small figure of merit (0.057ns/(μm⋅V)).