A Fully Integrated Dual-Output Continuously Scalable-Conversion-Ratio SC Converter for Battery-Powered IoT Applications

This paper proposes a fully integrated dual-output continuously scalable-conversion-ratio (CSCR) switched-capacitor (SC) converter that increases the overall power conversion efficiency (PCE) beyond that of the conventional dual-output SC converters. The structure employs proposed dual-output CSCR SC stage and channel SC stage to transfer charges to two output load voltages (VOUTs) with high PCE. Also, the converter is controlled by analog switching frequency modulation (ASFM) and digital flying capacitance modulation (DFCM) loops to regulate both V(OUT)s simultaneously. The proposed converter is fabricated using a 180 nm CMOS process, and regulates V-OUT of 1.1-1.6 V and 0.55-0.95 V with an input voltage of 1.5-1.9 V. In measurement, the proposed converter achieves a maximum PCE of 85%, and an average PCE of 78.6% for the available V-OUT ranges. Moreover, the converter exhibits the maximum I(OUT)s of 21 mA and 4 mA, respectively.