• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 63 subscribers
  • Views 372 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.

TPS23730: Option-2 ORing & Transformer for 12V/24VDC adapter (or) PoE+ input

Pradeepkumar Selvaraj1
Prodigy 200 points
Part Number: TPS23730
Other Parts Discussed in Thread: LM3478

We are developing a Small cell indoor unit.

Our Power Requirements: Input power is PoE+ (or) 12V/24VDC adapter. Output Power will be around 12V, 3.5A.Option-2 ORing is planned. Attaching the block diagram herewith. PFA.

We have queries on transformer selection and OR-ing option-2.

1) As per our requirement, the transformer should be capable of accepting a wide range of primary input 12V- 48V. So, could you please tell us that a single transformer solution is possible and provide us the transformer part details?

2) Option-2 ORing is provided in the application notes only using the TPS23735 chip with 48VDC, but not using TPS23730. Also no EVAL schematics we can see using option-2 ORing with a 12V adapter. Could you please provide us the reference schematics for using OPTION-2 ORing solution for 12/24V adapter.

Thanks,

Pradeep.S

  • 0
    TI__Mastermind 21320 points

    Hello Pradeep, 

    Thanks for the question. At this time, we do not have a wide-Vin design for 40W. The challenge that exists here is that wide-Vin designs require a transformer that can accept a wide input voltage, as you pointed out. In order to do this, the transformer inductance is lower, which leads to higher primary current, which leads to higher thermals. As we up the power, this problem is amplified. 

    To that end, we do not have a wide-Vin design at that power level at this time. Of course that is something we want to address in the future. I am not aware of any transformers available for this. Often we design the transformer ourselves, or work closely with the vendor to spec it. 

    Another option you could look into is using a boost converter for your adapter, to make it 48V, and then feed that into one of our designs like a normal Option 2 adapter. 

    If this post answers your question, please indicate so by marking this thread as resolved. Thank you.

     

    Regards, 

     

    Michael P.

    Applications Engineer

    Texas Instruments 

  • 0 in reply to Michael Pahl
    Prodigy 200 points

    Hi Michael,

    Thanks for your response.

    As you have suggested, we have decided to incorporate a boost converter of 48V/2.5A output in our design.

    LM3478 based boost converter design is planned to use. we have arrived at a webench design using the same chip. Could you please check whether the attached design is a good one for our application? Please provide your comments.

    Thanks

    Pradeep. S

  • 0 in reply to Pradeepkumar Selvaraj1
    TI__Mastermind 21320 points

    Hey Pradeep, 

    I would suggest following up with the team that supports this device. They are going to be your best resource on this, since I focus on the PoE PD. 

    If this post answers your question, please indicate so by marking this thread as resolved. Thank you.

     

    Regards, 

     

    Michael P.

    Applications Engineer

    Texas Instruments