A Reconfigurable and Extendable Single-Inductor Single-Path Three-Switch Converter for Indoor Photovoltaic Energy Harvesting

This article proposes a single-path three-switch (1P3S) single-inductor dual-input dual-output (SIDIDO) converter to manage power among a photovoltaic (PV) module, battery, and load for indoor PV energy harvesting. For low duty-cycle applications, the 1P3S converter increases efficiency in the PV-to-battery-to-load path by eliminating inductor-sharing power switches. This article also proposes a reconfigurable controller to achieve reconfigurability and extendibility that the 1P3S converter can be reconfigured as a dual-path three-switch (2P3S) SIDIDO converter, combined as a dual-path six-switch (2P6S) SIDIDO converter, or extended as a paralleled-1P3S converter for high energy efficiency in various applications with different PV and load power profiles. To identify each converter's advantageous applications, the efficiencies of the 1P3S, reconfigured 2P3S, and combined 2P6S converters were analyzed under dynamic PV and load powers. The chip is fabricated in the 0.5- μm CMOS process with a 1.24-mm2 chip area. The measured peak efficiencies for the 1P3S, 2P3S, and 2P6S converters are 95.0%, 95.2%, and 90.0%, respectively, while the measured quiescent currents are 210, 130, and 140 nA, respectively. Compared with the state-of-the-art 2P3S and 2P6S converters, the reconfigured 2P3S and combined 2P6S converters with the proposed IC, respectively, achieve higher efficiency through appropriate switch sizes and ON-time optimizations.