A Gate Overdrive Protection Technique for Improved Reliability in AlGaN/GaN Enhancement-Mode HEMTs

On a GaN smart power integrated-circuit platform, a monolithically integrated gate-protected high-voltage AlGaN/GaN enhancement-/depletion-mode high-electron mobility transistor (HEMT) has been proposed. It can sustain large input gate voltage swing (> 20 V) with enhanced safety (no gate failure observed) and improved reliability (no observable shifting of the threshold voltage), and the breakdown voltage is not sacrificed. Such a protection scheme with a wide input gate bias range also facilitates simple and reliable connections between the gate driver circuits and the power switches without the level shifter circuits for conventional GaN Schottky gate power HEMTs.