• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 62 subscribers
  • Views 323 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.

LM5576 / Unstable switching pulse

S.Satoshi
Guru 21675 points

Hi All,

Our customer found unstable switching pulse on their evaluation board as attached. It can not been seen at light load but the switching pulse will be unstable at mid and heavy load. Please confirm the setting of external components and let me know which components should be optimized.

Best Regards,

Sonoki / Japan Disty

LM5576 unstable switching pulse.pdf
  • 0
    Guru 21675 points

    Hi All,

    I found that the Cramp used at customer's board was 680pF and it's larger than the recommended value. I replaced from 680pF to 220pF (22uH x 10^-5 = 220p), then I could resolve this issue.

    Now I'd like to understand the mechanism of this behavior by using larger Cramp. I understand that the larger Cramp will cause of slower ramp slope. Then I'd like to understand why this slower ramp slope will cause of unstable switching.

    Your comments will be appreciated.

    Best Regards,

    Sonoki