• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 62 subscribers
  • Views 793 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.

TPS2378EVM-105: Questions about TPS2378EVM-105 schematic

Nicky Lim
Genius 3195 points
Part Number: TPS2378EVM-105


Hello,

I have 2 questions about TPS2378EVM-105 schematic.

1. Center Tap Ground of  Both side of Transformer(T1) are same. It looks not good for isolation.

   Could you let me know why Grounds not separated? Is there any special reason?

2. Can I remove FET(Q1) which is connected to RTN?

   If does not use this FET, what happened?

Please let me get your answer.

Regards,

Nicky

Questions_TPS2378EVM.pdf

  • 0
    TI__Genius 9230 points
    Hi Nicky,

    1. The data side (where the Ethernet PHY is placed) & power side (where the PD controller & converter are placed) should be sitting on ground planes isolated from each other as well as isolated from the bob smith plane. You may isolated the data side BS plane from the PoE side BS plane, but it isn't really necessary given that the isolation of the other planes is sufficient. Ultimately, you will just have two quasi-earth ground planes when one would just do.

    2. To connect to RTN, all you need to do is unpopulate J5 & use the "SRTN" port of the J6 terminal. (the on-board designations can be confusing) No de-soldering needed. The purpose of Q1 is for non-standard dual PD designs.

    Thanks,
    Thomas A.