Adaptive Multi-Mode ACDC Control Circuit Driven By Gallium Nitride

To address the global energy crisis and increasingly strict energy efficiency regulations (such as the US DoE Level VI and the EU CoC V8), traditional silicon-based flyback AC-DC power supplies, due to their low conversion efficiency (65%-85%) and insufficient power density, are unable to meet the requirements of high-power fast charging. This paper proposes an adaptive multi-mode AC-DC power supply control chip circuit based on gallium nitride (GaN) switches. By implementing load adaptive switching control of modes - heavy-load quasi-resonant (QR), medium-load frequency modulation (PFM), light-load pulse width modulation (PWM), and standby burst mode (Burst Mode) - the efficiency is significantly improved and the standby power consumption is reduced (<30mW). At the same time, considering the high-speed switching characteristics of GaN, a push-pull stepwise drive circuit is designed to meet the requirements of high-speed switching. Experimental results show that this scheme can achieve a 120W output power at 220V input, with an average efficiency of over 92% for the full load, and the switching tubes precisely achieve valley conduction (verified by simulation). Compared with the traditional scheme, its power density, efficiency, and standby power consumption have been significantly optimized, meeting the latest energy efficiency standards, suitable for high-power fast charging scenarios, and having broad application prospects.