An Inductorless DC–DC Converter for an Energy Aware Power Management Unit Aimed at Microbial Fuel Cell Arrays

This paper introduces an inductorless dc-dc converter for an energy-aware power management unit aimed at microbial fuel cell (MFC) arrays capable of performing a dc step-up gain of up to 10× and achieving efficient maximum power point (MPP) tracking. Due to the MFC´s varying power profile over time, identifying and selecting the best MFC harvesting point enhances efficiency and overall power delivery. Currently, MFC series or parallel connections have limited application due to the voltage reversal issue present in MFCs; this makes time multiplexing harvesting a more reliable approach. However, each time a new MFC is allotted the time for harvesting, a new MPP is required. The proposed converter dynamically adapts to achieve MPP as well as adjust the converter´s own power consumption to maximize efficiency. The converter was designed and fabricated in 0.18-μm CMOS process and shows a maximum efficiency of 65% for 1.6 mW of input power.