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TPS54201: 10KHz noise of TPS54201 output .....

Part Number: TPS54201 Dear Sirs, My customer found their TPS54201 output will have 10KHz noise sound. The sound seem came from inductor or capacitor! Below is schematics and waveform. Customer use DC 3.3V for PWM input for test now. Can you help to advice which point we can pay attention? Thanks.

Hi Peter, So you have used a pure DV voltage level instead of PWM signal to dimming? You can try to increase the capacitor value between LEDs. What's the cap value that you used? It is not clear in the picture. Another suggestion is increasing the cap value connected to FB pin. BR Sean

Hi Peter, Is there any update? Have you found the root cause? BR Sean

Hi Sean, 1. update clear schematics. 2. already have 2x22uF caps in parallel between LED. what value will you suggest to use? (in red circle) 3. had test 1uF cap connect to FB pin but still fail! Is there any suggest else? Thanks.

Hi Peter, Since there is no 10kHz signal inside of TPS54201, I guess it may come from the power supply, so can you try with a 12V DC power to test? And what's the frequency of the PWM dimming signal? It is 10kHz? We recommend >50kHz. BR Sean

Hi Sean, OK! i will check with customer and make sure the 12V input is from DC power supply and try again! BTW, the PWM signal that customer use for testing now is pure DC level.(3.3V).

Hi Peter, Yes, please try again and give me an update later. BR Sean