A Soft-Charging-Based SC DC-DC Boost Converter with Conversion-Ratio-Insensitive High Efficiency for Energy Harvesting in Miniature Sensor Systems
IEEE Transactions on Circuits and Systems I
This paper introduces a fully integrated switched-capacitor (SC) DC-DC boost converter suitable for energy harvesting in miniature sensor systems with varying harvesting source and battery voltages. Unlike the conventional SC DC-DC boost converters, where efficiency is optimized only for a few topology-dependent voltage conversion ratios (VCRs), the proposed soft-charging-based SC converter achieved VCR-insensitive evenly high efficiency for a wide range of input and output voltages. The measured peak efficiency and average efficiency are 85.3％ and 83.6％, respectively, for 1.8V regulated output voltage and a wide range of input voltages (0.95？1.8V). Also, peak efficiency of 88.9％ and average efficiency of 87.6％ are achieved for a wide range of a battery’s output voltages (3.0？4.2V) and a 1.2V harvesting source input voltage.
IEEE Trans. Circuits Syst. I Regul. Pap. 67, 3601？3612 (2020)