• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 64 subscribers
  • Views 726 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.

LM2621: Layout Example

tateo yamashiro
Guru 10890 points
Part Number: LM2621

Hi,

We got a question from customer about LM2621.
Could you help us?

[Question]
They are designing the board based on layout example in datasheet. They have  questions.

Q1. Rfb2 is connected to the PGND terminal. They think Rfb2 should be connected to SGND. Also PGND terminal is far from power GND and be connected by narrow trace. Are there any possibility that these connections will cause a problem?

Q2. SGND is colse to the Power GND. Is there any possibility that this connection will cause a problem?

Best Regards,
tateo

  • 0
    TI__Guru* 76745 points
    Hi Tateo-san,

    Thank you for considering the LM2621. I agree with your customer that it is better option to reference Rf2 to SGND, although it doesn't mean the example layout will actually cause problem. No doubt that the good practice should be using SGND for all control signals and PGND for power circuit.

    Regarding the SGND connection to PGND, they should be connected to PGND anyway. The key is not to place the PGND on the path of the power current, which is what has been done on the example layout.

    Hope this clarifies. If this answers your questions, please respond by clicking "This solved my issue" button.

    Best Regards,
    Youhao Xi, System and Applications Engineering, APP-BMC-BCS, TI