A Discrete Multilevel Active Gate Driver for GaN HEMTs to Optimize the Switching Behavior

A simple implementation of a cost-effective multilevel gate driver employing solely commercially available components is introduced. Using the proposed driver, the system is able to adjust the applied gate voltage and gate resistance individually with five stages to successfully control the switching transient of GaN HEMTs. This is beneficial to experimentally determine optimized gate switching schemes in the laboratory. An investigation of seven different multilevel driving schemes with varying timing in the switching patterns and resistance combinations was conducted. The results demonstrate that the discrete multilevel gate driver exhibits superior performance in terms of faster turn-on transients with reduced turn-on energy losses as well as overshoots and undershoots, in comparison to conventional gate drivers with a constant gate resistance.