Power management unit for long-range harvester-assisted wireless sensor node.

Energy harvesting has become increasingly important nowadays. This solution allows the development of autonomous devices, avoiding the use of batteries, that do not have a large duration and can be harmful to the environment. Some energy harvesters provide very low voltages, that are therefore unable to supply what is required by some electronic devices. This can be solved with the use of step-up voltage converters. Moreover, some of these are not able to provide enough power for continuously supply to sensor nodes. With the help of a voltage monitor we can ensure that the power is only transferred to the sensor node whenever the capacitor storing the energy provided by the harvester is charged enough. In this work, a Power Management Unit (PMU) for a long-range harvesterassisted wireless sensor node is proposed. The PMU is able to adapt the output voltage of the harvester to the required voltage for the sensor node, and store its energy in a capacitor. It also ensures that power transmission only occurs when the capacitor is charged enough