• State Resolved
  • Replies 1 reply
  • Subscribers 62 subscribers
  • Views 28 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

LM51551-Q1: Coupled inductor in SEPIC architecture

Behnam Madadnia
Intellectual 340 points
Part Number: LM51551-Q1

Tool/software:

Dear Engineers,

I want to use this reference design (PMP40488) for one of my application.

I noticed if I used coupled inductor for L3 and L4 I will get better performance and the value of the positive rail and rail will be closer to each other:

Based on the test report there is a little bit difference between positive and negative rail:

Based on the bill of material of the reference design, it seems, they have used two separate inductors for L3 and L4 and not a coupled inductor:

 I wonder If I use couple inductor the results will be different? or I can not gain that much? what is your suggestion should used the same BOM for having a reliable performance? 

Regards

  • +1
    TI__Expert 5505 points

    Hi Behnam,

    Thanks for reaching out.

    Indeed, the inductors are not coupled in this reference design.

    You can try using coupled inductors and see if the output rails have less difference. However a small difference depending on the load is normal if one rail is only cross-regulated.

    To have a reliable performance like in the test report, you should use the same BOM.

    Best regards

    Moritz