A High-Efficiency Wide Output Range Reconfigurable Capacitive-Sigma DC–DC Converter

A 5-to-0.4 $\sim$ 1.2-V reconfigurable capacitive-sigma dc – dc converter with 98.4% peak efficiency is presented. By input-series and output-shunt an efficient unregulated 2:1 switched-capacitor (SC) converter with a reconfigurable hybrid Dickson Buck converter, the proposed converter achieves high efficiency for the entire output voltage and current ranges. Besides, the proposed converter also demonstrates decent regulation and transient responses. The prototype achieved 98.4% and 90.4% peak efficiency at 1.2-and 0.4-V output, respectively. The output shows a static error of 1.1 mV and under-/overshoot voltages of $-$ 23 and 23.8 mV with 0.1% settling time of 25 and 30 $\mu$ s, respectively, over 2-A load range. Compared with the prior state of the arts, the converter improves the peak efficiency by 1.5% at voltage conversion ratio (VCR) $=$ 4.2 and by 4.9% at VCR $=$ 12.5.