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Original question:

TPS92512: Audible noise from Inductor

TPS92512: Audible noise from Inductor

Jay Kim
Intellectual 475 points
Part Number: TPS92512

TPS92512: Audible noise from Inductor - Power management forum - Power management - TI E2E support f...

e2e.ti.com
Part Number: TPS92512 Hello, Upon attached schematic, audible noise generated from Inductor(L1 and L3) when dimming. - Using PWM frequency 16.kHz : Barely

Had change different types of inductor to trying get rid of audible noise but still not find solution yet.

- PWM Frequency : 4kHz

- Switching Frequency : 750kHz

Below two photos are output current upon PWM(4kHz) duty.

I can see there's ripple current and guess it's the reason of audible noise.

Need help guide me to eleminate ripple current by seeing schematic on my previous post.

  • 0
    TI__Mastermind 28655 points
    Hello Jay,

    That ripple is at around 60 KHz so I don't think you're hearing that. What is causing that current? It's the PWM frequency at 4 KHz. Trying changing the PWM frequency and see if it changes the audible frequency. So what is RT set to on this board? that looks like 60 KHz but the sch shows RT at 200K or 400K depending on which circuit.

    Best Regards,
  • 0 in reply to Irwin Nederbragt
    TI__Mastermind 28655 points
    Hello Jay,

    I have not heard back from you so I believe you may have solved the issue.
    The thread will close now but will reopen if you reply.

    Best Regards,