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 (
$V_{\mathrm {OUT}}$
s) with high PCE. Also, the converter is controlled by analog switching frequency modulation (ASFM) and digital flying capacitance modulation (DFCM) loops to regulate both
$V_{\mathrm {OUT}}$
s simultaneously. The proposed converter is fabricated using a 180 nm CMOS process, and regulates
$V_{\mathrm {OUT}}$
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
$V_{\mathrm {OUT}}$
ranges. Moreover, the converter exhibits the maximum
$I_{\mathrm {OUT}}$
s of 21 mA and 4 mA, respectively.