• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 64 subscribers
  • Views 686 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

Original question:

LM5576: Radiated EMI performance, Layout issues?

LM5576: device getting damaged

Bart
Expert 6460 points
Part Number: LM5576

Hi Team,

continuing https://e2e.ti.com/support/power-management/f/196/t/709097 - the LM5576MH is still getting damaged in our design.

This happens probably when voltage is being turned on. Below is the schematic.

Can you please help us solving the issue?

Thank you,

TI Customer

  • 0
    TI__Guru 72702 points
    Hi Bartosz,

    What is the applied input voltage? Also, is it possible to capture the waveforms of the event that causes damage during startup?

    As mentioned previously, it's critical to locate the input ceramic cap close to VIN and PGND of the IC.

    Regards,
    Tim
  • 0 in reply to Timothy Hegarty
    TI__Expert 6460 points
    Hi Tim,

    the input voltage is 60VDC -68VDC.

    It's not possible to capture the waveforms, because the damage happens in 10% -15% of all devices / finished products brought back from the field.

    Staff reports that on first switch-on the device doesn't work.
    On one board we have LM5576MH, LM5017MR/NOPB plus LM5010AMHE/NOPB.
    The DC/DC are supplied with 50-60 VDC. Each one is separated with 7446631010 filter. We use PLC communication between devices - communication over power.

    Maybe it is important that LM5576MH are used for powering led matrix. Led matrix are multiplexed. It means that for some time (us/ms) DC/DC have no lead.

    Regarding location of the input ceramic cap close to VIN and PGND of the IC -> Is 3 mm distance too long ? We have two ceramic capacitors 2x 2u2 /100 V X7R.

    Thanks for your feedback and help.
    TI Customer
  • 0 in reply to Bart
    TI__Guru 72702 points
    Hi Bartosz,

    Please check input filter damping in case the input voltage overshoots during startup. I will follow up directly by email.

    Regards,
    Tim
  • 0 in reply to Timothy Hegarty
    TI__Guru 71905 points
    This issue is being resolved offline.