Electronic Device and Method for the Maximization of the Average Power Extracted from a Vibrational Harvester

Circuit device (10) for the maximization of the average power provided to a passive diode bridge rectifier (30) that supplies an electric load by a vibration energy harvester (20) coupled to an external source of vibrations having a determined and arbitrary shape and frequency, wherein said harvester (20) comprises at least one reactive component (22) in its equivalent circuit at the output terminals (24) and wherein the input voltage of the device (10) coincides with the input voltage of the passive diode bridge rectifier (30) connected to the output terminals (VAB) of the harvester (20), wherein said device (10) is configured to draw from the output terminals (24) of the harvester (20) a compensation current (iin) equal and opposite to the current flowing through the reactive component (22), independently of the shape and frequency of vibration and independently of the time shape and amplitude of the output voltage (VAB) of the harvester (20), the device (10) further comprises a power circuit composed of at least one first transistor (Mp) and one second transistor (Mn), connected by means of the respective drain terminals, for adapting the compensation current (iin) to the opposite of the current flowing through the reactive component (22), and a control circuit composed at least of an operational amplifier (13) and a hysteresis comparator (14) for managing the turn on and the turn off of the first and second transistor (Mp, Mn), wherein the output of the operational amplifier (13) is connected to the positive input terminal of the hysteresis comparator (14).