Methodology for Large-signal Loss Characterization of Ferroelectric Class II MLCC in High-frequency Range

Owing to its high dielectric constant and high energy density, Class II multi-layer ceramic capacitor (MLCC) using BaTiO 3 as the dielectric material has become a popular choice in high power-density converters, resonant switched-capacitor (RSC) converters particularly. When used as the primary energy storage/transfer elements in these applications, Class II MLCCs are exposed to large-signal and high-frequency excitations superimposed on bias voltage/electric field, while the loss characterization provided in manufacturer datasheets is based on small-signal measurement results. This paper develops an electrical loss characterization methodology based on a novel resonant-Sawyer-Tower (Res-ST) circuit for Class II MLCCs, under large-signal and wide-frequency-range excitations. A 10uF X5R MLCC rated at 16V from TDK is selected as the capacitor under test and measurement results are presented and the measurement results show a strong dependence of power loss on both excitation frequency and bias voltage.