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TPS23861: Tps23861 USES semi auto, disconnects I2C, and some tps23861 boards can be supplied with power, and some cannot.

Part Number: TPS23861

Hi sir, madam,

  Now the customer  to do the 16-port management switch(USES TPS23861), but now the customer disconnects the I2C (TPS23861 and MCU have no communication), some boards can be powered supply, some boards can not be powered supply. Excuse me, what caused this?

  • Hi Dave,

    Can you confirm that when you say "can be powered supply" it means the PSE can turn on the port and supply power to PDs through the ethernet cable? Assuming the answer is yes, can you check the the operating mode of the PSE devices on different boards? If the port is configured in auto mode, the port will turn on automatically whenever there is a valid PD connected. Otherwise, the PSE will wait for a turn on command from the host. Thanks. 

    Best regards,

    Penny

  • Dave,

    I wanted to check in as we have not heard back from you in a week.

    Please let us know if there is anything else we can do to assist...otherwise, we are going to assume this thread is resolved.

    Thank you for your interest in PoE products from TI,
  • Hi Penny,

      I am very sorry for not replying to you because I was on a business trip recently.

      Cannot supply refers to the PSE ports unable to open (no voltage on cable, PD side), different boards are semi-automatic mode, some problems board (not power), some of the board is working properly. 

  • Hi Dave,

    If the device is set in semi-auto mode and it loses I2C communication from host, it is expected that the port doesn't turn on. Since in semi-auto mode, the port always wait for a turn on command from the host after a valid PD is connected. Please check TPS23861 datasheet section 7.4.3 for semi auto operations. Thanks. 

    Best regards,

    Penny