An energy harvesting interface (70; 70') having a first input terminal and a second input terminal (25") configured to be connected to respective terminals of a first storage element, and a first output terminal and a second output terminal (26") configured to be connected to respective terminals of a second storage element, wherein the first and second input terminals (25', 25") are adapted to receive an electrical input signal (V IN), and the first and second output terminals are configured to supply, to the second storage element, an electric-current supply signal (I OUT) that is a function of an electric storage current (I L, I ON) supplied by the first storage element, the energy harvesting interface (70; 70') comprising: - a first switch and a second switch coupled together in series, between the first input terminal and the second output terminal (26"); - a third switch and a fourth switch connected together in series, between the second input terminal (25") and the second output terminal (26"); - a first charge-transfer element, coupled between the first input terminal and the first output terminal; - a second charge-transfer element, coupled between the second input terminal (25") and the first output terminal; - a first electrical-signal-detecting device, coupled across the second switch, configured to detect whether the electric storage current (I L, I ON) that flows through the second switch reaches a first threshold value (I TH), said electric storage current (I L, I ON) being associated to the electrical charge stored in the first storage element; - a second electrical-signal-detecting device, coupled across the fourth switch, configured to detect whether the electric-current supply signal (I OUT) that flows through the fourth switch reaches a second threshold value (I p /K) higher than zero and lower than the first threshold value (I TH); and - a control logic (60, 70) configured to: close the first, second, third, and fourth switches (30a, 30b; 31a, 31b) until the electric storage current (I L, I ON) reaches the first threshold value (I TH); open the first switch, thus generating the electric-current supply signal (I OUT) to supply the second storage element through the first charge-transfer element by discharging the first storage element; and keep the first switch open as long as the value of the electric-current supply signal (I OUT) is higher than said second threshold value (I p /K). - a first switch and a second switch coupled together in series, between the first input terminal and the second output terminal (26"); - a third switch and a fourth switch connected together in series, between the second input terminal (25") and the second output terminal (26"); - a first charge-transfer element, coupled between the first input terminal and the first output terminal; - a second charge-transfer element, coupled between the second input terminal (25") and the first output terminal; - a first electrical-signal-detecting device, coupled across the second switch, configured to detect whether the electric storage current (I L, I ON) that flows through the second switch reaches a first threshold value (I TH), said electric storage current (I L, I ON) being associated to the electrical charge stored in the first storage element; - a second electrical-signal-detecting device, coupled across the fourth switch, configured to detect whether the electric-current supply signal (I OUT) that flows through the fourth switch reaches a second threshold value (I p /K) higher than zero and lower than the first threshold value (I TH); and - a control logic (60, 70) configured to: close the first, second, third, and fourth switches (30a, 30b; 31a, 31b) until the electric storage current (I L, I ON) reaches the first threshold value (I TH); open the first switch, thus generating the electric-current supply signal (I OUT) to supply the second storage element through the first charge-transfer element by discharging the first storage element; and keep the first switch open as long as the value of the electric-current supply signal (I OUT) is higher than said second threshold value (I p /K). close the first, second, third, and fourth switches (30a, 30b; 31a, 31b) until the electric storage current (I L, I ON) reaches the first threshold value (I TH); open the first switch, thus generating the electric-current supply signal (I OUT) to supply the second storage element through the first charge-transfer element by discharging the first storage element; and keep the first switch open as long as the value of the electric-current supply signal (I OUT) is higher than said second threshold value (I p /K).