Origin and Consequence of the Voltage Dependence of Ferroelectric Class 2 Multilayer Ceramic Capacitors

Two processes can be distinguished, leading to an immediate as well as a long-term capacitance dependence on DC voltage of class 2 Multilayer Ceramic Capacitors (MLCC). Both processes are related to the ferroelectric properties of class 2 materials.

We review the physical background of MLCCs’ voltage-dependent capacitance, present models for this dependency, and show how impedance may change. We will also discuss the possible influence of the voltage signal on the equivalent series resistance and the resulting device losses.