• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 64 subscribers
  • Views 526 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.

LM53600-Q1: When is isolation of PGND and AGND required?

Julio Apps
Expert 3665 points
Part Number: LM53600-Q1

Team,

In section 11.1.1 of the LM53600-Q1 in the datasheet it mentions : 

"The PGND trace, as well as PVIN and SW traces, should be constrained to one side of the ground plane." Is this implying that we recommend isolated grounds?

When is isolation of PGND and AGND required? Let's say i am operating 12Vin and 5V out with a transient load of 300mA peak every few ms. Would you recommend separating the GND's since my load is transient in nature. Will this power level even result in my ground shifting.

  • 0
    TI__Expert 6860 points

    Julio ,

    Here is the explanation :

    The Noiser ground plane as well as sensitive AGND is connected through Power PAD . 

    ---Ambreesh 

  • 0 in reply to Ambreesh Tripathi
    TI__Mastermind 25590 points
    Julio,

    Any design with bad PGND/AGND layout will result in some GND shift - obviously less for less current. 300mA could be enough to change the performance of the board if accompanied by poor layout, especially when the load is transient in nature. We recommend separating the GNDs and connecting them through the Power PAD so that this possible issue doesn't have to be considered if the board does not perform as expected.

    -Sam