A Continuously-Scalable-Conversion-Ratio SC Energy-Harvesting Interface with Exponential DCO for Wide Range Output Power Tracking

This paper presents an energy harvesting interface circuit utilizing a continuously-scalable-conversion-ratio (CSCR) switched-capacitor (SC) converter. The circuit integrates an exponential digital control oscillator (DCO) and a compact capacitive divider to facilitate maximum power point tracking (MPPT) across a wide power spectrum, ranging from 30 to $6,056 \mu \mathrm{~W}$, which is 20 times broader than previous approaches. Fabricated using a 180 nm CMOS process, the prototype chip achieves a peak power conversion efficiency of ${9 1. 5 \%}$ and can deliver a maximum output power of 6.05 mW.