MLCC Noise Howling and Countermeasures

Jacktang

MLCC Noise Howling and Countermeasures [Copy link]

MLCC - Multilayer Ceramic Capacitors, also known as chip capacitors, can cause noise and howling problems...

Sound comes from the vibration of objects. Sound waves with a vibration frequency of 20Hz~20 kHz can be recognized by the human ear.

MLCC makes a whistling sound, which means that MLCC vibrates with a large amplitude (microscopically large, less than 1nm) under the action of voltage.

Why does MLCC vibrate?

We must first understand a natural phenomenon - electrostriction.

Under the action of an external electric field, all substances will produce expansion and contraction deformation - electrostriction.

For some ferroelectric materials with high dielectric constants, the electrostrictive effect is severe, which is called the piezoelectric effect.

The piezoelectric effect includes the direct piezoelectric effect and the inverse piezoelectric effect.

宋元浩

Thanks for sharing your experience

led2015

Electrostrictive Some polycrystalline materials, such as lead zirconate titanate ceramics, have spontaneously formed molecular groups, so-called electric domains, which have a certain polarization, and the length along the polarization direction is often different from that in other directions.

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What is the countermeasure?