• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 2 answers
  • Subscribers 64 subscribers
  • Views 333 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

UCC28063A: UCC28063A Inductor audio noise

James Su5
Expert 1340 points
Part Number: UCC28063A

My Power in VAC264V full load 300W condition have “Zizi…” audio noise, and  VAC85~240V input no “Zizi…” audio noise, please get me a command to solve this audio noise Issue, thanks !

PS, all condition PFC Performance is normal

BR James

  • 0
    TI__Guru 58335 points

    Hello James,

    If the audible noise is low frequency and sounds like the humming of transmission lines this is due to low frequency power conversion.  The PFC makes the input current track the line.  The inductor currents peak will vary at 2X the line frequency and will produce a low frequency hum.  This is similar to what you hear off the power lines if you go for a walk at night.  If this is the issue that you are having potting the boost inductors will help resolve this issue.

    Make sure the design is not going into and over current or over voltage fault.  If this is occurring it can result in audible noise.

    Make sure the minimum frequency of your design is above the audible range.  It needs to be greater than 25 kHz.

    Lastly there is a 300W EVM that you can evaluate to see if it meets your audible noise criteria.

    Regards.

     

  • 0 in reply to Mike O'
    Expert 1340 points

    Hi Mike,

    Customer doesn't potting the boost inductors plan,
    No over current or over voltage fault status during VAC264V input condition, we need to finetune any to reduce “Zizi…” audio noise.

    Regards.
    James

  • 0 in reply to James Su5
    TI__Guru 58335 points

    Hello James,

    If the converter is not entering a fault mode the noise is either low frequency or high frequency.

    Is the minimum switching frequency above 20 kHz?  If it is not change the inductance so the minimum frequency operates at greater than 25 kHz.  That should reduce the noise if it is high frequency.

    If the minimum frequency is above the audible range this is the low frequency noise discussed previously.  If the customer does not want to use potting material he could try varnishing the inductors.  A lot of magnetic manufactures will do this for you if you request it.

    The other option is try an inductor from a different magnetic manufacture if it is low frequency noise.

    Regards,

  • 0 in reply to Mike O'
    Expert 1340 points

    Hi Mike,

    Minimum switching frequency setting 45KHz and inductance is 120uH.

    Regards,
    James

  • 0 in reply to James Su5
    TI__Guru 58335 points

    Hello James,

    It sounds like the design is making audible noise due to low frequency.  I would try varnishing the inductor and gluing down any components that might be vibrating.

    Regards,