Hello everyone. I am working on a project where I use raspberry pi and a speaker. I'm using an amplifier module for the speaker which operates on 12v while raspberry pi needs 5v hence I use CA-1235 DC-DC converter which converts 12v to 5v for the raspberry pi. Now, I can hear buzzing noise in the speaker all the time. If I power up my raspberry pi and the amplifier module with two different power supplies, then the noise was gone ( Earlier, I used 5v amplifier module for the speaker but that was not loud enough and hence I switched to 12v one but that time too I heard the buzzing noise and it went away when I powered up with two different 5v adapters ). But I want my project to run on single power input. What shall I do?

 

https://forum.allaboutcircuits.com/...mplifier-and-raspberry-pi.201554/post-1918331

 

It appears that the voltage conversion module does not provide isolation between the input and the output. That is often the cause of such problems. Getting a step-down module with adequate isolation is the solution.

 

@Clar_a584, what is a "ground loop separator" in this case?

 

@Clar_a584, what is a "ground loop separator" in this case?

A simple 1:1 audio coupling line transformer would likely work to break the conducted noise (that the RPi is well known for) transfer between modules but might limit frequency response if cheap ones are used. Separate power supplies (isolated modules) is usually the best solution.
https://www.amazon.com/HiLetgo-EI-14-Coupling-Isolation-Transformer/dp/B073PXK2RX

 

It might be cheaper and less complicated to use an siolated power converter module.