A Bipolar ±13 mV Self-Starting and 85% Peak Efficiency DC/DC Converter for Thermoelectric Energy Harvesting

Abstract

This paper presents a novel converter for boosting the low-voltage output of thermoelectric energy harvesters to power standard electronic circuits. The converter can start up from a fully depleted state of the system off a bipolar ±13 mV input and can boost it to output voltages of up to 5 V. The converter comprises two transformers, one for each polarity that are multiplexed between an oscillator (used during startup) and a flyback converter (used during normal operation). To eliminate leakage currents in the input stage, the unused converter is completely turned off at startup and both converters are automatically shut off if the input power is found to be too low. Measurement results of the converter designed in a 180 nm CMOS process demonstrate a peak end-to-end conversion efficiency of 85% and nearly perfect impedance matching over the full input voltage range. This is the first time that a converter for ultra-low bipolar input voltages achieves the same performance as a unipolar converter.

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“…From this board, it selectable performance up to 5V. The standard use of this board can be seen in [35][36], which looked into the production of power from ultra low voltage. Figure 14 depicts an example of a block diagram of TEG based power supply.…”

Power Supply of Wireless Sensors Based on Energy Conversion of Separated Gas Flows by Thermoelectrochemical Cells

“…A promising technical solution is provided in [39]. The proposed converter can start from a fully discharged state at an input voltage of ±13 mV and increase its output voltage to 5 V. The experimental results demonstrated efficiencies of up to 85% and near-perfect impedance matching over the entire input voltage range.…”

A ±0.5-mV-Minimum-Input DC-DC Converter with Stepwise Adiabatic Gate-Drive and Efficient Timing Control for Thermoelectric Energy Harvesting

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