A simple control scheme for improving light-load efficiency in a full-bridge LLC resonant converter

In this paper, a load adaptive phase-shift control is proposed for the full-bridge LLC resonant converter to improve light-load efficiency. The proposed method reduces the effective duty ratio and the magnetizing current. Therefore, the core loss on transformer and the turn-off switching loss on switches are significantly reduced. To confirm the validity of this study, the prototype with 320∼400V DC input, 12V/40A DC output is experimented.