A VCO-Based MPPT Circuit for Low-Voltage Energy Harvesters

摘要

Thermal energy harvesting has many key challenges such as getting a sufficient output power, while achieving maximum power efficiency from thermoelectric generators (TEGs). A new VCO-based MPPT circuit for low-power applications is introduced. The proposed MPPT circuit is used in conjunction with Pelliconi charge pump forming a low-power thermal energy harvesting system. This system models the temperature difference between TEG module layers by 0.25V that is boosted to 3V. A prototype is implemented using UMC 130nm technology process, which achieves 61.6 % power efficiency, with output voltage level approximately 3V at maximum load current of 60 μA.