Multi-Topology DC-DC Converter for Low-Voltage Energy Harvesting Systems

Abstract

This paper deals with the design and analysis of a multi-topology DC/DC converter (MT-DC/DC), suitable for ultra-low voltage energy harvesters, such as thermoelectric, photovoltaic or biofuel-cell generators. MT-DC/DC was proposed and investigated as proof of concept with ultra-low voltage cold-start capability (deep sub-hundred mV) and implemented in a standard 130 nm CMOS fabrication process. By the use of multiple operating modes, such as the self-oscillation mode, inductive boost-mode based on transformer reuse technique, and tapped-inductor boost-mode, the MT-DC/DC achieves coverage of a wide range of the input voltages. The design also includes a maximum power point tracking control loop, specifically designed for energy harvesting applications, and is capable to deliver more than 2.5 mW of power while maintaining a regulated output voltage of 1.2 V.