TPS54229: Humming noise on the inductor of the regulator

SHYAM THILLAINATHAN61

Part Number: TPS54229

Hi, We are using TPS54229DDAR in our design and here is the schematic:

The parts used are:

C503, C602, C505: C1005X7R1H104K050BB
C600, C601, C507, C508, C509: GRM188R61C106KAALD
C504: GRM155R61H474KE11D
R521: RC0402FR-0793K1L
R522: RC0402FR-0722K1L
C506: GCM1555C1H220JA16D

ISSUE: Problem we are seeing is that there is a very slight humming sound coming around the inductor. Is there any value change that might help us with this issue?

over 5 years ago

0 Jason Wang (BSR-MV) over 5 years ago

TI__Genius 9550 points

hi,

Please find my answer.

1. Normally, the humming noise comes from MLCC capacitor, see below blog's intruduction.

Blog "How to reduce acoustic noise of MLCCs in power applications",

link: http://e2e.ti.com/blogs_/b/powerhouse/archive/2016/08/09/how-to-reduce-acoustic-noise-of-mlccs-in-power-applications?keyMatch=how%20to%20reduce%20mlcc&tisearch=Search-EN-Everything&keyMatch=How%20to%20reduce%20acoustic%20noise%20of%20MLCCs%20in%20power%20applications&tisearch=Search-EN-Everything

2. if you confirm the humming noise comes from inductor, suggest change inductor with another vendor.

3. Double confirm if the device operation stable or not when the humming noise happen. If the operation is not stable, I think you shold resolve the unstable issue firstly.

Let me know your feedback if you have.

0 SHYAM THILLAINATHAN61 over 5 years ago in reply to Jason Wang (BSR-MV)

Prodigy 70 points

Hi Jason,

Thanks for the feedback. We completely isolated the above power section from our design and we are still seeing the issue. We are suspecting the other power regulators used. We are trying to see if changing the MLCC to <KRM>, <ZRA/ZRB>, <GJ4/GJ8> series capacitors in MURATA helps. Further can you please help by reviewing the below schematic section as we feel the issue is arising from this region:

Here are the part details for the capacitors:

C80, C88, C92, C98: CGA6P3X7S1H106K250AB, C3225X7R1H106M250AC (or) C1210C106M6PACTU
C75, C78, C86, C93, C99: CGA3E2X7R1H223K080AA (or) GCM188R71H223KA37D
C79, C81, C84: C3216X5R1E476M160AC (or) C3216X5R1C226M160AB‎
C82, C85, C90, C91, C95, C97: CGA3E1X7R1C105K080AC (or) CL10B105KO8VPNC

0 Shawn Nie over 5 years ago in reply to SHYAM THILLAINATHAN61

TI__Genius 10070 points

Hi,

I think the schematic is okay, only one concern is the layout, only two vias are used to connect SW pin with the inductor, what is the part number of inductor? And what is the load when you hear the noise?

Shawn

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TPS54229: Humming noise on the inductor of the regulator