A Monolithic GaN Power Stage with Low Propagation Delay and High Reliability Level Shifting for High Frequency Power Converter

In this article, a monolithic gallium nitride (GaN)-based half-bridge power stage is proposed for high frequency power converter. A level shifting technique with buffering device and shielding capacitance is designed to perform communications in half-bridge topologies with high reliability and low propagation delay. To prevent the missing pulse or output latch during deadtime, a negative voltage pull-down circuit is designed. Implemented with a $0.25\mu \mathrm{m}$ 15-V enhanced mode GaN (eGaN) process, this work consists of optimized delay matching, monolithic gate drivers and power high electron mobility transistors(HEMTs) as well. The implementation results show that this work can achieve a propagation delay of no more than 6.5ns, a delay mismatch within 2.5ns and a CMTI capability above 150V/ns at 30Mhz switching frequency.