A 20 mV Input Boost Converter With Efficient Digital Control for Thermoelectric Energy Harvesting

This paper presents a low power boost converter for thermoelectric energy harvesting that demonstrates an efficiency that is 15% higher than the state-of-the-art for voltage conversion ratios above 20. This is achieved by utilizing a technique allowing synchronous rectification in the discontinuous conduction mode. A low-power method for input voltage monitoring is presented. The low input voltage requirements allow operation from a thermoelectric generator powered by body heat. The converter, fabricated in a 0.13 mu m CMOS process, operates from input voltages ranging from 20 mV to 250 mV while supplying a regulated 1 V output. The converter consumes 1.6 (1.1) mu W of quiescent power, delivers up to 25 (175) mu W of output power, and is 46 (75)% efficient for a 20 mV and 100 mV input, respectively.