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TPS2547: Would TPS2547 disconnect all ports when attaching to a hub?

Lauren Mayfield
Expert 6890 points
Part Number: TPS2547
Other Parts Discussed in Thread: TPS2546

Hi,

I want to recommend the TPS2547 to a customer who needs a USB charging and data transmit solution (capable of ID’ing if Apple and Android devices for charge control). He does not need/want variable voltage Power Delivery, just the 5V at up to 2.4A charging with ID. He will be using this with both a USB-A 2.0 connector, and a USB C connector, which will only have 2.0 data.

He tried to implement this previously with the TPS2546, but it was attached to a hub, and any time he went to attach a device for charging, it would disconnect ALL ports on the hub, causing a reset on other devices. After trying this with multiple hubs it had the same result.

My question is would the TPS2547 also have this issue? Is there a part you could recommend that does not have this issue with the same capability?

Thanks,
Lauren

  • 0
    TI__Genius 9630 points

    Hi Lauren,

    During attachment, the TPS2546 will go through an OUT discharge (depending on mode it is switching into). This is also true of the TPS2547. Are the other ports connected to the OUT pin of the TPS2546? 

    Thanks,

    Emma

  • 0 in reply to Emma Hoying
    TI__Expert 6890 points

    There was a pair of the TPS2546 EVMs being used, attached to the downstream ports of several hubs, with beefy power supplies. Attaching one device for charging on one port would make the USB HUB reset, and disconnect with the other port as well as the port that got plugged.  I tried this with several upstream hub chips, and eventually gave up.

  • 0 in reply to Lauren Mayfield
    TI__Genius 9630 points

    Hi Lauren,

    Can you describe your setup and test procedure in more detail \with pictures? Is the USB Hub disconnect when devices other than the TPS2546 are attached? If so, what kinds of devices. Also, what mode is the TPS2546 in?

    Thanks,

    Emma

  • 0 in reply to Emma Hoying
    TI__Expert 6890 points

    Hi Emma,

     

    This was a long time ago so it's hard to recall details.

     

    I had a 4 port hub, two ports were used by internal keyboard and mouse. The other two ports both went through the 2546, and when you plugged something in like an Apple or Android which could be higher current charge, after a few seconds, when the 2546 decided to charge, the hub controller would reset all ports.

    Is this behavior supposed to occur? Or was the TPS2546 configured incorrectly somehow?

  • 0 in reply to Lauren Mayfield
    TI__Genius 9630 points

    Hello Lauren,

    The TPS2546 should not disconnect all the ports, this is not expected behavior of the device.

    To clarify, you had two ports connected to the TPS2546? The TPS2546 is a single-port controller, so it sounds like the TPS2546 could be connected incorrectly, which could cause issues. Could you provide a schematic for analysis?

    Thanks,

    Emma

  • 0 in reply to Emma Hoying
    TI__Expert 6890 points

    It was two downstream ports on 4 port hub, each connected to one of the TPS2546 EVMs.

  • 0 in reply to Lauren Mayfield
    TI__Expert 7035 points

    Hi Lauren,

    If the TPS2546 EVM is used correctly, it should not behave like this. It will be difficult for us to determine what the problem is without more details. If able, can you send us a schematic and detailed test procedures?