Monolithically Integrated GaN Ring Oscillator Based on High-Performance Complementary Logic Inverters

A gallium nitride (GaN) ring oscillator based on high-performance one-chip complementary logic (CL) inverters is demonstrated on a conventional p-GaN gate power HEMT (high-electron-mobility transistor) platform. It manifests the feasibility of the multiple-stage monolithic integration of GaN CL gates, the most energy-efficient digital circuit configuration, and consequently the potential of deploying CL circuits in the all-GaN power integration as peripheral circuits with higher energy efficiency. Thanks to the successful monolithic integration of enhancement-mode p-channel and n-channel field-effect transistors, the integrated CL inverters in this work present remarkable performances, including stringent rail-to-rail operations, substantially suppressed static power dissipation at both logic `low' and `high' states, suitable transition threshold voltages of ~2.0 V (40% of the common 5-V supply) and wide noise margins above 1.8 V (36% of 5 V).