Step-Up DC-DC Converter Supplied by a Thermoelectric Generator for IoT Applications

This research work aims to design and prototype a DC-DC converter to step up the low voltage of a small, low-power thermoelectric generator (TEG). The system is based on an inductive boost converter and attains a regulated output voltage of 1.2 V. The design's optimisation was based on simulation and experimental validation and it was implemented with only ten low-cost commercial off-the-shelf (COTS) components. To reduce complexity, the low-side switch MOSFET of the boost converter is directly driven by an LC oscillator, switching at 1.25 MHz. For loads above 20 k Omega, the converter ensures voltages higher than 1.2 V, supplied by the TEG voltage of 0.5 V, while registering identical efficiency values to those of more complex and expensive CMOS-integrated solutions. These designed features suggest applications in remote IoT nodes and portable devices, delivering sufficient power to backup the supply of corresponding sensing and communication low-power circuits, reducing the necessity of battery replacements or increasing their lifetime.