• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 31 subscribers
  • Views 591 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.

TAS5709A: TAS5709A EMC problem

Hoi Wa Ip
Intellectual 720 points
Part Number: TAS5709A

Dear TI expert,

We have a 2.0 BT speaker product which deploys TAS5709A for audio power stage. We conducted EMC check on the product and noticed that it failed at 400MHz check point. Would you please kindly advice how we can improvement EMC performance of TAS5709A?  Below is a picture of TAS5709A output stage and EMC measurement data. Peter 

      

  • 0
    TI__Expert 3470 points
    Hoi Wa Ip,

    Thank you for reaching out to us and for your interest in our devices. I will look into this and get back to you tomorrow. In the meantime, I sent you a connection request so that you can send me your layout.

    Regards,
    Brian Angiel
  • 0 in reply to Brian Angiel
    Intellectual 720 points
    Hi Brian,
    I have sent you the design files through private email. Would you please help review my design and give me comments where appropriate. I really want to close this case and keep moving forward. Thank very much for your help.

    Best regards,
    Peter
  • 0 in reply to Hoi Wa Ip
    TI__Expert 3470 points

    Hi Peter,

     

    Are you designing a two-layer board? That seems to be the case based on the documentation you sent, and I just wanted to verify.

     

    Below are some guidelines that should help improve EMC performance. If you require more assistance, it would helpful to have the BOM and design files themselves, rather than a PDF of the board layout.

     

    • Schematic
      • Add more decoupling caps (one per power pin)
    • Layout
      • Keep decoupling caps as close to the device as possible and route other signals around them
      • Have a solid GND plane (no breaks in the plane)
        • If you do have breaks in your GND plane and you run output lines over those breaks, this will decrease EMC performance
        • As a general rule, running square waves overs breaks in a GND plane will decrease EMC performance
      • Maintain short GND loops
    • Components

      • Look for low-DCR shielded inductors
      • Look for low ESR capacitors

     

    I hope this information is helpful to you, and if you would like more help, please let us know.

     

    Regards,

    Brian Angiel