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TPS23730: TPS23730

kiran surve
Prodigy 110 points
Part Number: TPS23730

Hi,

We have designed Isolated Class 6 POE power supply as per reference schematics PMP22494_RevA_SH2.SchDoc using TPS23730 IC.

Classification resistors CLSA = 31.7 ohms (27 ohms + 4.7ohms) & CLSB = 130 ohms (120ohms + 10 Ohms)

Would the circuit operate for all the below Ethernet switches with Type 1, Type 2 and Type 3 classes? 

Regards,

KIRAN SURVE

  • 0
    TI__Mastermind 23371 points

    Hi KIRAN,

    Thanks for reaching out!

    This PD will request Class-6 power from PSE. You will need a Type-3 or -4 PSE meanwhile it has an enough power budget to support the full Class-6. If PSE could not provide the Class-6 power either due to PSE's type limitation or power budget, PSE normally will offer Class-4 (Type-2 PSE) or Class-3 (Type-1 PSE) power depending on the PSE's type and power budget. 

    TPS23730's TPH, TPL, BT pins will have different Hi-Z/L status to indicate the actual Class the PD negotiates with the PSE. A downstream MCU can adjust the load by these pin status. 

    Best regards,

    Diang

  • 0 in reply to Diang Xing
    Prodigy 110 points

    Hi Diang,

    With our PD design for class 6 power using TPS23730  having Classification resistors CLSA = 31.7 ohms (27 ohms + 4.7ohms) & CLSB = 130 ohms (120ohms + 10 Ohms) and if my load is 25W would the circuit work with Type 2 802.3at class 4 PSE ? 

    Regards,

    KIRAN SURVE

  • 0 in reply to kiran surve
    TI__Mastermind 23371 points

    Hi KIRAN,

    This Type-2 PSE should only handshake as Class-4 in your case. And yes, if your PD input power is 25W this circuit can work (The PD power rating is for its input power, which is PD's load / efficiency).

    Best regards,

    Diang