An Anti-Overcharged High-dV/dt-Immunity Capacitive Level Shifter With Dynamic Discharge Control for Half-Bridge GaN Driver

摘要

This paper presents an anti-overcharged high-dV/dt-immunity capacitive level shifter with dynamic discharge control (DDC) for half-bridge GaN driver. The DDC prevents overcharge of the floating power supply capacitor during high negative dV/dt transitions and is suitable for a wide variation range of negative dV/dt transitions of floating power supply. Moreover, a fault-logic blanking block is introduced to guarantee the robust of output logic during ultra-high dV/dt transitions. The proposed Level shifter is fabricated in a 0.18-µm BCD process and occupies an active chip area of 0.034mm^{2. Simulation results demonstrate that the propagation delay is less than 0.8ns at 50V level shifting and keeps almost constant when the floating ground ranges from -3V to 50V. The positive dV/dt immunity is 300V/ns. The negative dV/dt is 170V/ns under the condition that the level shifting capacitor does not discharge to floating power supply.}