A High-Efficiency Li-ion Battery Switching Charger with Dual-Path Three-Level Buck Converter

  • Woo Joong Jung Korea university
  • Yun Ho Lee
  • Sung Min Yoo
  • Tae Hwang Kong
  • Jun Hyeok Yang
  • Hyung Min Lee
Keywords: Dual-Path, Flying capacitor, Li-ion battery charger, Loop-free calibration, Self-balancing, Three-level buck converter


This paper proposes a li-ion battery switching charger with a three-level DC-DC buck converter adopting a loop-free auto-calibration technique for self-balancing of flying capacitors. The proposed switching charger provides four operation modes as the Li-ion battery voltage level. It is designed by 0.13-μm CMOS BCD process and used two flying capacitors of 4.7 μF each and an inductor of 10 μH with a DC resistance (DCR) of 100 mΩ as output components. The supply voltage is 9 V and the load condition is 2.7-4.2 V and the maximum load current is 1.5 A. The simulation peak efficiency of constant current mode is 93.2% at 1 MHz switching.