Because of the Thanksgiving holiday in the U.S., TI E2E™ design support forum responses may be delayed from November 25 through December 2. Thank you for your patience.

  • State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 64 subscribers
  • Views 2368 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.

TPS23754: Schematic for Vout = 5V

na na78
Guru 16770 points
Part Number: TPS23754
Other Parts Discussed in Thread: , TPS23756EVM, TPS23756

Hi

We are considering PoE+ system using TPS23754.

Topology : Forward
Vout : 5V

So, we are referring two EVM schematics, TPS23754EVM-383 and TPS23756EVM.


1. I made the following schematic in combination, for generating Vout=5V.
Could you please check the following schematic, and please tell me comment If you could find issues?

2. We are assuming the following pulse transformer and the peripheral circuit
(The pulse transformer is not included in RJ45).



Have you ever been designed PoE+ system with such a circuit?
If you have reference design and information about it (including peripheral circuit constant), could you advise me?

BestRegards

  • 0
    TI__Mastermind 40650 points
    Hi na na,

    Any particular reason your design was split up? Is it due to wanting to use a 12V adapter and want to keep a sense resistor rather than the current sense transformer. The input current under low voltage input conditions can heat the resistor and can be less efficient. This why we recommend the TPS23756 solution. I recommend to stick with the whole EVM design for a known working and optimized solution.
  • 0 in reply to Darwin Fernandez
    Guru 16770 points

    Hi Darwin

    Thank you for your reply.

    I understood if 12V adapter is used TPS23756 should be chosen because of UVLO (Vc).

    I found another reference PMP5818.  Could you please see the following question?

    I think this would offer 5V/4.8A output using TPS23754.

    In this design, JA4270-AL (now FCT1‑50M22SL or PA2328NL) is used as transformer.

    As for PA2328NL,  the voltage applied to Vc of TPS23754 seems to be 12V.

    Could it be possible configuration?

    BestRegards

  • 0 in reply to na na78
    TI__Mastermind 40650 points
    Hi nana,

    Yes, PMP5818 is a well known working solution as shown by it's great performance in its test report. The BOM shows that it was been tested with the PA2328 so you can use this transformer. Note that the converter was designed for an input voltage range of 33-57V.
  • 0 in reply to Darwin Fernandez
    Guru 16770 points
    Hi Darwin

    Thanks.
    Let me open other thread if I had more questions.

    BestRegards