A Triple-Mode DC–DC Converter With Wide Input and Load Ranges for Energy Harvesting in IoT Edge Nodes

A triple-mode dc-dc converter with wide ranges of input and load for energy harvesting in Internet-of-Things edge nodes is reported. The proposed energy harvester is designed and fabricated in a 0.18-<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> CMOS process. It demonstrates MPPT, automatic buck-boost operation, stable operation in proper energy-distribution path based on the changes of load and input source, and efficient energy conversion control with peak efficiency up to 88.7%, with load transient response time of <inline-formula> <tex-math notation="LaTeX">$ < 450~\mu \text{s}$ </tex-math></inline-formula>, a wide input range of 1.2 – 4 V and an output range of 1 – 4 V, as well as a maximum load up to 50 mA.