Piezoelectric Materials for the DC-DC Converters Based on Piezoelectric Resonators

This paper presents a generic representation of the six switching sequences of the dc-dc converters based on piezoelectric resonators. In addition, the estimation of current density and voltage limitations of lead zirconate titanate and lithium niobate resonators are given. A comparison between these piezoelectric materials is carried out. Then, we propose a lithium niobate-based piezoelectric resonator design that reduces spurious modes, while providing a quality factor of 3700 and an electromechanical coupling factor k t 2 of 25.5 %. Experimental results demonstrate the operating principle for input-output voltage of 60-20 V around 6 MHz for a wide power range 2-32 W. A peak efficiency of 93.6 % is obtained at 16 W. A power density of 128 W/cm 3 for the designed resonator is reached for input-output voltage of 60-20 V.