A Dual-Input Bidirectional Three-Level Battery Charger Using Coarse-Fine VCF Balancing and Frequency Foldback Control for Foldable Mobile Applications. - Woojin Hong; Hyebong Ko; Jinwoo So; Woonhyung Heo; Yonghwan Cho; Jeongdu Yoo; Ho-Sung Son; Youngwoo Chung; Dong-Joon Kim; Byeonghyeon Jin; Minkyu Kwon; Kyungmin Park; et al. (IEEE J. Solid State Circuits, 2025)