MLCC Acoustic Noise Mitigation via Appropriate Design
MLCC Acoustic Noise Mitigation via Appropriate Design
复制标题
通过适当的设计减轻 MLCC 噪声
DOI：
10.1109/estc55720.2022.9939506
复制
发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Tamas Krausz
中科院分区：
文献类型：
--
作者：
C. Covaci;Florin Burza;Tamas Krausz
电子设备中出现的电容器鸣音现象是由于电介质的材料钛酸钡（BaTiO 3）。钛酸钡具有两个主要的机电性能，压电性和电致伸缩性，当施加电场时，这使得电容器的内电极振动。除了这个缺点之外，钛酸钡是一种高介电常数材料，并且因为它，小的等效串联电感（ESL），小的等效串联电阻（ESR），良好的频率响应和其他优点得以实现。电容器的振动不是问题本身，但不幸的是，它通过焊膏传递到印刷电路板（PCB），PCB可以开始以20 Hz-20 kHz的可听频率振动。通过改进设计，我们设法衰减了这些电容器引起的噪声。在本文中，我们提出了一个机械解决方案，涉及PCB固定在系统中，两个电气设计改进，以改变所研究的LED驱动器的电气行为。第一个设计改进集中在电压尖峰消除。第二种方法是对电容器进行预充电，以降低施加在电容器上的电应力。通过加速度计和声压级（SPL）测量对设计改进进行了监测，并显示出衰减的振动和声学噪声。
The singing capacitors phenomenon appears in electronic devices due to the material the dielectric is made of, Barium Titanate (BaTiO3). BaTiO3 has two main electromechanical properties, piezoelectricity and electrostriction, which make the capacitor's inner electrodes vibrate when an electric field is applied. Besides this disadvantage, Barium Titanate is a high-level permittivity material, and because of it, small equivalent series inductance (ESL), small equivalent series resistance (ESR), good frequency response, and other advantages are fulfilled. The capacitor's vibration is not the issue itself, but unfortunately, it is transmitted to the printed circuit board (PCB) via the solder paste, and the PCB can start to vibrate in the audible frequency of 20Hz-20kHz. By improving the design, we managed to attenuate the acoustic noise caused by these capacitors. In this paper, we present one mechanical solution that involves the PCB fixation in the system and two electrical design improvements to change the electrical behavior of the LED Driver studied. The first design improvement is focused on voltage spike elimination. The second one involves pre-charging the capacitors to lower the electric stress applied to them. The design improvements are monitored with both accelerometer and sound pressure level (SPL) measurements and showed an attenuated vibration and acoustic noise.