Improved power management circuitry for energy-harvesting devices

摘要

An energy-harvesting device 10, particularly a wireless sensor device, contains detector circuitry 12 for controlling the operation of a power management module 14 of the energy-harvesting device 10. The detector circuitry 12 comprises an input 13 for receiving an electrical input representative of a level of harvestable power, and a trigger (which may be a Schmitt trigger) coupled to the input 13 and operable to generate an activation signal for switching on the power management module 14. The trigger is configured to generate the activation signal when a threshold level of harvestable power is detected, and does not generate the activation signal the level of harvestable power is not detected. A method of controlling the operation of a power management module 14 of an energy harvesting device 10 includes receiving an electrical input representative of a level of harvestable power; generating an activation signal for switching on the power management module 14 upon detecting at least a threshold level of harvestable power; and not generating the activation signal upon detecting less than the threshold level of harvestable power. The device 10 may harvest radio frequency (RF) power or solar power, and maximum power point tracking may be synchronized with the presence of the input power.