Multilayer ceramic capacitor induced audible noise simulation

Multilayer ceramic capacitors (MLCCs) are one of the most widely used capacitors. Their small size, high capacitance, high reliability and low cost make them ideal for miniaturized electronic devices. However, their piezoelectric effect may cause the deformation of the capacitor associated with the applied voltage. Even worse, the deformation may cause the PCB vibration and potential noise radiation, which can be a problem for devices designed to be quiet, such as cellphones, earbuds, laptops, etc. This paper introduces how MLCCs can cause PCB vibration and noise radiation problems by simulating a single MLCC with piezoelectric effect. And then, a methodology is proposed on how to quantify the MLCC as vibration load source. Moreover, a simplified process is illustrated to simulate the MLCC induced noise radiated from circuit boards. Finally, a couple applications are demonstrated by using the developed process.