Device and relative method for scavenging energy

An energy scavenging device, comprising:

• an electromagnetic transducer responsive to accelerations;
• a power switching stage coupled to said electromagnetic transducer;
• an output capacitor coupled to said power switching stage and having first and second terminals;
• and
• a controller coupled to said electromagnetic transducer and configured to sense current therein and to drive said power switching stage to selectively short-circuit said electromagnetic transducer and direct current flowing through said electromagnetic transducer to charge said output capacitor;
• said power switching stage comprising
• a high-side switch and a low-side switch coupled in series to short-circuit said electromagnetic transducer when both closed, and a common terminal between the high-side switch and low-side switch being coupled to said first terminal of said output capacitor, and
• a high-side diode and a low-side diode each coupled between said second terminal of the output capacitor and said common terminal of said high-side switch and said low-side switch.

A method of scavenging energy using a device comprising an electromagnetic transducer configured to generate a current in response to accelerations impressed thereto, a power switching stage input with current generated by the electromagnetic transducer, a network of controlled switches configured to alternately deliver on output nodes of the power switching stage an output current that does not invert its sign and to short-circuit the electromagnetic transducer, an output capacitor coupled between the output nodes and having first and second terminals, a controller having a sensor coupled to the electromagnetic transducer to sense current flowing therethrough, the controller being configured to drive the switches of the power switching stage, the power switching stage comprising a high-side switch and a low-side switch coupled in series to short-circuit the electromagnetic transducer when both closed, and a common terminal between the high-side switch and low-side switch being coupled to the first terminal of the output capacitor, and a high-side diode and a low-side diode each coupled between the second terminal of the output capacitor and the common terminal of the high-side switch and the low-side switch, the method comprising:

• monitoring the current flowing through the electromagnetic transducer using the controller;
• and
• driving the switches of the power switching stage, using the controller, to short-circuit the electromagnetic transducer, and depending on the current, selectively continuing to short-circuit the electromagnetic transducer and directing the current flowing through the electromagnetic transducer to charge the output capacitor until the current through the electromagnetic transducer nullifies.