A Stacked Piezoelectric Converter Using a Segmented IDT Lithium Niobate Resonator

Piezoelectric resonators promise to increase dc-dc converter power density by replacing inductive components. However, piezoelectric resonators are not direct circuit level replacements for inductors, requiring new topologies. In this paper, we present a stacked converter using two piezoelectric resonators, providing improved efficiency at low conversion ratios. This converter is realized with a lithium niobate thickness-shear mode resonator with interdigitated electrodes that allow the two resonators required for the topology to be realized as tightly matched sub-resonators on the same substrate. The 180 V to 60 V converter operates between 6.15 MHz and 6.35 MHz and achieves a resonator-level power density of $\text{1.34}\;\text{kW}/\text{cm}^{3}$ .