A Highly Integrated 3-Phase 4:1 Resonant Switched-Capacitor Converter With Parasitic Loss Reduction and Fast Pre-Charge Startup

This brief proposes a highly-integrated 3-phase ( 3Φ) 4:1 resonant switched-capacitor (ReSC) converter with parasitic capacitor soft charging for Internet-of-Things devices, reducing the current stress at the point of load. Both the 3Φ resonant operation and the parasitic loss reduction schemes improve the power conversion efficiency. Also, this 3Φ-ReSC converter implements a flying capacitor pre-charge scheme to guarantee a safe startup. The chip, fabricated in a 65-nm CMOS process, occupies a silicon area of 1.39 mm
²
. We achieve a peak efficiency of 85.5% and a maximum output current of 130mA, in a mm-sized solution, with an input range of 2.3 V - 2.5 V.