I have a PCB designed with the LMZ21700SILT device. I like it for the small package due to size constraints on my board. However there is considerable audible noise associated with the 22uf input & output MLCC SMT caps (22uf, X7R). I was able to minimize the audible noise by going with more expensive through hole caps. I now have a new design that I am working on in which I would like to use the same LMZ21700SILT part but not if I have the same audible noise issue. I want to go back to the SMT caps. I have researched the methods to resolve the MLCC cap & audible noise issue but they are not practical. I think the part itself may exhibit audible noise due to its physical interface with the PCB & vibration & that's one of the reasons I can't get rid of the noise altogether.
I've followed the PCB layout recommendations in the data sheet.
What is your experience with audible noise with this part & what suggestions do you have to eliminate it?
My schematic & BOM are revealed in the image below which is extracted from the data sheet.
Thanks.