Switched-Inductor Capacitive Interface

Abstract

In contrast to the inductor-less solution given in Chap. 6, using a switched-inductor in conjunction with an input capacitor gives viable prospectives: it could cover a wider power range, and promises a less complex circuit design. Unlike conventional switch-mode converters, the innovative concept introduced here allows voltage conversion between $V_\text {g}$ and $V_\text {buf}$, and continuous MPP harvesting without a complex feedback control, or any pulse-width modulator. Therefore, the inverter is triggered by a detector, e.g. the LMD of Chap. 7. In addition, for synchronized out-of-phase switching of the two power converter switches, a coupled active diode method is introduced. Even though this simplistic approach both, continuous as well as averaged FVT in a DCM mode, is possible with high efficiency, at DC and AC voltage waveforms. After the derivation of design rules and operating limits, proof-of-concept studies with a PCB implementation give further insights. The design of the PCB implementation performs continuous FVT with DC and AC generator voltages. Finally, a chip implementation shows self-sustaining operation for averaged FVT of AC voltages, i.e. from the electromagnetic transducer.