• State TI Thinks Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 2 answers
  • Subscribers 62 subscribers
  • Views 232 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.

TPS23731EVM-095: TPS23371 can have 2 ports of POE+DATA?

Yogesh Singhal
Prodigy 175 points
Part Number: TPS23731EVM-095
Other Parts Discussed in Thread: TPS23731

We plan to use TPS23731 device and make PoE speakers

we connect the RJ45 , LAN DATA +poE  cable to first speaker. we understand we can define a address to this port and connect with a PC to control speaker.

we are looking..

1) can we use TPS23731 to loop the LAN cable? , in First speaker LAN IN and Lan Out.  Lan out of first speaker goes to Speaker 2 as Lan input ..and so on..

2) It means tps23731 board, must have POE+ DATA ports 2 numbers always..

can we do this way?

pl suggest

  • 0
    TI__Mastermind 21320 points

    Hello, 

    The TPS23731 supports the power off the Ethernet cable only, so i can only speak to the power portion. 

    So do you need power over both ethernet cables, or just one? 

    You could have two ports but only one send power. 

    Would that work?

    I do not think you can connect two PSE's to the same PD -- that might disrupt the detection. It might be able to be done, but it would take some experimentation. I cannot confirm that will work. 

    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 175 points

    Dear Michael

    thanks for the reply, 

    my query is...i plan to make POE speakers of 15w each. Now can i connect these 10 speakers in daisy chain to each other (using CAT5 cable).

    WHen connected in daisy chain , can i powered them and address them individually.

    i do want to do parallel wiring.

    rgds

    yogesh singhal

  • 0 in reply to Yogesh Singhal
    TI__Mastermind 21320 points

    Hello Yogesh,

    Thank you for the clarification. 10 nodes at 15W each would be a "non-standard" solution. 

    Please consider that each cable connection has power loss, each PD has power loss,  and each  PSE has power loss. Additionally, the voltage will be dropping from node to node, so the first node has to be very high voltage. I calculate that if each node has 100m of cable, the first output voltage will need to be around 141V. The PoE standard is 57V maximum. Plus, the output power of the first node would need to power each of the other nodes, plus account for all of the power loss in the cables. Roughly calcuating, that is about 15W*10W  + cable losses = ~ 314W. The PoE standard only goes to 90W. 

    So in conclusion, this would be a custom system that would be very high power. We do not make PoE parts that can handle that level of power. I do not think anyone does. The highest we have seen is around 120W, using two PD's in parallel. 

    I would suggest either lowering the number of nodes connected together, lowering the power per node, or look into power switches instead of PoE. You can send power over ethernet cables with a power switch, but it will just be a switch instead of being compliant with any standard. 

    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 175 points

    Dera Michael

    thanks for the feedback and clarification. our basic need was to have daisy chain system , to avoid multiple wiring from base unit/system.

    Can we have some solution to have daisy chain in PoE speakers.

  • 0 in reply to Yogesh Singhal
    TI__Mastermind 21320 points

    Hello, 

    Please accept my connect request and I can send  you what we have. 

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

     

    Regards, 

     

    Michael P.

    Applications Engineer

    Texas Instruments