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TPS23861 POE problem

Other Parts Discussed in Thread: TPS23861, TPS2379, TPS23861EVM-612

Hi every body!
I have done a POE (using TPS23861) circuit with camera axis P1357-E(Figure 43. Automatic 4-Port Operation Schematic , in the TPS23861 datasheet). But I have a problem, it is:
Link: http://www.ti.com/product/tps23861
- Case 1: While POE circuit powered (VDD = 3.3V; VPWR = 48V), I connect network cable between camera with POE (RJ-45 port), camera will be powered by POE circuit, Camera works well (OK).

- Case 2: While POE circuit not powered, I connect network cable between camera with POE. Then, I will supply power for POE circuit. Camera haven't been powered. Camera didn't work! I don't why?
I want camera will work same the case 1 after I supply power for POE!
Can you please tell me solutions to solve that problem?
Many thanks!

  • ctm ctm

    We are looking into this problem and will advise you of our initial findings

    shortly.

    Jerry Steele

  • Using our 100M EVM board for the TPS23861 which
    is the same schematic for the auto 4-port I could
    not duplicate the problem.

    Our testing was done with two loads:
    1. TPS2379 evaluation board
    2. Cisco 7942 IP phone

    The following conditions were evaluated:
    1. VPWR (48 volts) applied first, then VDD (3.3V)
    2. VDD applied first, then VPWR

    All combinations of the above conditions turned on
    successfully with either plugging the CAT5 cable into
    a powered EVM, or connecting the cable to an un-powered
    EVM and turning on power.

    The specifications in the manual for your camera certainly
    indicates it is specified for IEEE 802.af max 12.95 W or High
    PoE max 25.5 W which is a specification that should work
    ok.

    In the meantime we will discuss this problem in more detail
    with our applications engineers to see if we can shed any
    light on it.

    Do you have any other PoE load devices that you could
    test with your PSE?

  • Hi !

    Currently, I have only camera AXIS P1357-E that are PoE load devices.

    About "8.4.2 Inrush Protection" in TPS23861 datasheet, I think TSTART is cause in "case 2" which I said.

    TSTART default is 60ms. Is it short time?

    How do you think about that?

    I want try to change TSTART  = 120 ms (PSoC1 CY8C24123A communicates TPS23861 via I2C protocol). POE circuit will be change a little for I2C. In this case, TPS23861 is slave, SDAO connect to SDAIN, then they (SDA, SCL) will be pulled up to VDD by  1.8k resistor ; A3 was connected to GND. Is SLA (slave address) of TPS23861 "0x20"?

    Have you any project sample (source code) about that? 

    Many thanks!

  • We are looking at what we can provide for sample code, and should

    have an answer today.

  • Thank you for your valuable time and I look forward to hearing from you in the nearest time!

    Many thanks!

  • I am unable to provide any specific sample code, but I think this should be easy. You have your I2C connections and addressing correct, and you are probably aware that you simply need to write 20h into the Timing Configuration Register at 16h. If there are any other details on this I can help you with let me know.

    Jerry

  • Hi Gerald Steele!
    I have done a project about I2C communications between PSoC1 and TPS23861.
    I wrote 20h into the Timing Configuration Register at 16h successfully. I checked (First I wrote , then I read value of that Register , it is OK).
    But It can't slove problem (at case 1 and case 2) which I said.

    Case 1: Camera work well (OK). I read value of Port 1 Status Register of TPS23861.
    Value is 0x64 (CLASSIFICATION STATUS is Class 0, DETECT STATUS is Resistance valid).

    Case 2: Camera can't work.I read value of Port 1 Status Register of TPS23861, too.
    Value is 0x03 (CLASSIFICATION STATUS is Unknown, DETECT STATUS is Resistance too low).
    Can you detail "Resistance", please? What is it?
    Excuse me! Do you know email address of expert technical person in your company about POE and TPS23861?

    Because TPS23861 is new product.
    Many thanks!

  • Hi Gerald Steele!

    Have you any account skype?

    My account skype is: congtm.tts

    I want add your account skype to my contact list, easily to communicate more!

    Thanks!

  • Hi every body!
    Did you use TPS23861EVM-612 Module (using MSP430)?
    I have a problem. Can you help me, please?
    I want get status of registers 0x0C (Port 1 Status) - 0x17 (General Mask) (12 registers)
    and status of registers 0x60 (Port 1 Detect Resistance) - 0x67 (Port 1 Detect Resistance) (8 registers)
    while TPS23861EVM-612 Module running on auto mode or semi-auto mode or manual mode and there aren't any POE device  (please don't plug in any POE device to TPS23861EVM-612 Module).
    Can you send status results for me, please?
    Because I'm doing project about POE (PSoC1 and TPS23861), I want check my circuit which I did!
    Many thanks!

  • Hello,

    Did you use TPS23861EVM-612 Module (using MSP430)? Yes, you can find more detail in the EVM user guide which is online (starting on pg 18). The EVENT, PORT STATUS, and POWER STATUS registers are available with this "basic" code. For other registers the code would have to be modified by the user.

    I suggest using the provided TI Commander GUI for circuit debug as all of the internal device registers are available. You can also make use of the I2C command logging (traffic log) to get real world detail on the I2C commands and responses to help you with your coding.

  • Hi Eric Wright,
    I haven't any TPS23861EVM-612 Module.

    With PSoC 1, I can get status of those register.
    But I want to compare the TPS23861EVM-612 Module with my POE circuit (PSoC1 and TPS23861)
    because above it is problem which I have with my POE circuit.

    So, I need you help me. I need status results file(.txt, .log,..) if  you can check for me!

    Many thanks!

  • OK, I think I understand now. I will try to get the traffic log file from the EVM by this week and send it to you. Just to confirm, you would like to get the log with every port disconnected (no PD attached), right?

  • Hi Eric Wright,

    Right. No PD attached! 

    Thanks for your helps!

  • Here is the traffic log snapshot of the status polling cycle. This is from the EVM for one TPS23861 device with nothing connected to any of the four ports. Hope it helps.

    2014-09-05 17:02:48.096 hpa172-0 20:2814 1 [S] <W> SB {2E:INPUT VOLTAGE}

    2014-09-05 17:02:48.096 hpa172-0 20:2814 2 [R] <R> RW {C3 32*}:32C3:12995 [P]

    2014-09-05 17:02:48.100 hpa172-0 20:2815 1 [S] <W> SB {2C:TEMPERATURE}

    2014-09-05 17:02:48.100 hpa172-0 20:2815 1 [R] <R> RB {5B*}:5B:91 [P]

    2014-09-05 17:02:50.089 hpa172-0 20:2816 1 [S] <W> SB {10:POWER STATUS}

    2014-09-05 17:02:50.089 hpa172-0 20:2816 1 [R] <R> RB {00*}:00:0 [P]

    2014-09-05 17:02:50.093 hpa172-0 20:2817 1 [S] <W> SB {0F:PORT 4 STATUS}

    2014-09-05 17:02:50.093 hpa172-0 20:2817 1 [R] <R> RB {06*}:06:6 [P]

    2014-09-05 17:02:50.097 hpa172-0 20:2818 1 [S] <W> SB {0E:PORT 3 STATUS}

    2014-09-05 17:02:50.097 hpa172-0 20:2818 1 [R] <R> RB {06*}:06:6 [P]

    2014-09-05 17:02:50.101 hpa172-0 20:2819 1 [S] <W> SB {0D:PORT 2 STATUS}

    2014-09-05 17:02:50.101 hpa172-0 20:2819 1 [R] <R> RB {06*}:06:6 [P]

    2014-09-05 17:02:50.105 hpa172-0 20:2820 1 [S] <W> SB {0C:PORT 1 STATUS}

    2014-09-05 17:02:50.105 hpa172-0 20:2820 1 [R] <R> RB {06*}:06:6 [P]

  • Thanks for your help!

  • Hi every body!
    I want control each port ( turn on, turn off, reset) by TPS23861 ( via I2C).
    But TPS23861 can't work well.

    Option 1: I reset all port (write 0x10 to Reset Register). It is OK. TPS23861 can work well, all port will be reset.
    Option 2: I reset each port(write 0x01 to Reset Register). Example port 1, but port 1 not reset (port 1 turn off, but not turn on).
    I think port 1 will be reset? Can you tell me solutions to solve that problem, please?
    Option 3: I turn off each port, it is OK. But when i turn on each port, TPS23861 sometimes can work well.
    I refer Cool Down/Gate Drive Register. My range time between turn off and turn on > 5s.
    I want that when i turn on port, TPS23861 can work well. Can you help me?
    Many thanks!
  • I have problem to make the TPS23861 output 48V when I received the board.

    My design is based on the reference design,Auto mode. When I power on the board, I measured the 3.3V and 48V is ok. But the TPS23861 is always in detection mode,when 802.3 at type 4 PD is pluged in.

    This problem puzzled me for 3days,I even can not sleep well, for this abnormal. I have asked my friend in TI to support me,but it seems no one know this chip,at shanghai team. no support, so I try to find support from baidu. After struggle for this problem for 3days, I now try to find alternate solution. But by chance, I remove the 2.2uF capacitor from the port( between Vpwr and VDRN,the reference design is 0.1uF), and change the power to only supply line pair 12,and 36; after doing this modification, I'm excited to see the port can work now.

    The above is my experence, I shared here and expectiing can be helpful to someone.

  • Hi,

    Thanks for sharing your experience. Next time, if you have any questions with TI devices, you can always post your questions on e2e, and we will get back to you within 24 hours. 

    To answer your question, in the IEEE standard, the parallel signature capacitance should be lower than 0.15uF. That's why having 0.22uF caused your detection problem. In TPS23861 datasheet application section, we also listed the design procedure.  Thanks.

    Best regards,

    Penny