mp150 circuit,from the example of datasheet,The inductor have "zi"noise continuously. when I replace the inductors, the noise still exist in a lower voice. HOW to solve this problem?
Hi @554607919,
The audible noise is mainly caused by the MLCCs, inductors or transformers, when stressed under high-voltage pluses at frequencies that result in physical effect, such as the reverse piezoelectric effect on the coil or magnetostriction on the core.
Some ways you can dampen the audible noise could be:
- Shift the resonance frequency of the PCB as high as possible above the vibration frequencies. Adding more attachment points increases the PCB resonance frequency, OR
- Increase PCB damping and use mounting points with soft damping materials, OR
- A smaller PCB size increases the resonance frequency, OR
- weight of the board, OR
- using the modeled inductors.
Please refer to the article below on how to dampen/eliminate the audible noise:
Hope this helps.
Thank you
Saurabh