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AM625: POWER SUUPLY DESIGN || POE & DC JACK Power ORING [POE SUPPLY WILL BE PRIORITY]

Part Number: AM625
Other Parts Discussed in Thread: PMP22806, TPS23731

we have requirement of 12Volt [12W to 15W] POE Supply. 

we need your support to design Power Oring for POE & DC supply [Priority will be POE]:

We are providing both POE and DC Supply [12V DC Adapter] as a input supply source and for that we need to give priority to POE in case of both POE and DC Supply available.

Requirement:- So suppose if a device is running on DC Supply and in this condition POE supply entered then according to POE as a priority, supply need to switch power from DC Jack to POE and switching must be seamlessly so that device able to switch smoothly without Reboot. And now further by taking this scenario continue suppose POE Power supply removed [DC Adapter still plugged in] then device supply again get back to DC Supply as input source smoothly without Reboot.

So Kindly support us and provide ref. design of Power supply to set the POE as a priority as described above using PD Controller based solution.

 

We have also checked that  we can add Power MUX IC [TPS2121RUXR] for this kind of requirement so let us know if there is any challenge in PD controller based solution. 

 

We will keep Power MUX IC Based solution as other option. So please confirm that can we use Power Mux solution for the same requirement described above. And kindly provide HW configuration and ref. design for the Power MUX IC [TPS2121RUXR] based Solution. 

We want check and need your suggestion for both option according to reliability & Costing point of view so kindly provide your support.

Here attached link of ref. design of POE shared by TI earlier,

at - https://www.ti.com/tool/PMP8803

  • Hi Hemal,

    Thanks for reaching out!

    On the PoE PD side, I would recommend you to using Option 3 as the circuit below to enable seamlessly PoE PD <-> adapter transition.TPS23731 is recommended for your case considering TPS23731 has EMPS that can automatically maintain power signature when PD input power is low. For 12-V output TPS23731 circuit you can refer PMP22806 (www.ti.com/.../PMP22806).

    On the secondary side, a bi-directional oring circuit can be implemented. I can forward you to oring controller team for related questions.

    Best regards,

    Diang