A Single/Dual-Output Switched-Capacitor DC-DC Converter with Geometrically Arranged Soft VCR Transitions

Dynamic voltage scaling (DVS) enhances power efficiency in digital systems, particularly in small loT devices with limited power sources. Switched-capacitor (SC) DC-DC converters offer several benefits, including high integrability and cost reduction, when implementing DVS in small systems [1]. Reconfigurable SC DC-DC converters with fine-grained voltage conversion ratios (VCRs) [2], [3] have efficient wide voltage ranges. Those featuring dual output [4], [5] can further reduce the area overhead for multiple dynamic loads. However, reconfigurable SC converters may encounter charge redistribution losses when the VCR changes (Fig. 1, top left). Reordering all serially connected stages in a converter [6] can help, but the complex switching network between flying capacitors makes it challenging to expand converter stages to achieve a fine-grained VCR transition.