33.2 A 600V GaN Active Gate Driver with Dynamic Feedback Delay Compensation Technique Achieving 22.5% Turn-On Energy Saving
Jing Zhu, Yan Ding, Siyuan Yu, Weifeng Sun, Gang Shi, Siyang Liu, Sen Zhang
Abstract
Wide-band-gap power devices hold great promise for creating power-conversion systems that are smaller, faster and more energy efficient than silicon power devices. Benefiting from smaller parasitic capacitors and superior conductive characteristics of gallium-nitride (GaN) transistors, the switching frequency (fSW) of power converters can soar to several or even dozens of MHz. Meanwhile, the power efficiency can be significantly improved. However, increasing switching speed leads to large values of di/dt and dv/dt during turn-on transition period, which results in several reliability issues. The turn-on dv/dt will cause a displacement current to charge the C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">GD</sub> Miller capacitance of the complementary switch in half bridge, inducing false turn-on or even shootthrough, and the isolation structure will be influenced by the common-mode transient noise generated by dv/dt. In addition, EMI noise and gate oscillation will be even more severe as the values of di/dt and dv/dt increase.