• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 31 subscribers
  • Views 632 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LP-AM243: LP-AM243 Power Supply Error

Dylan Tarter
Intellectual 320 points

Part Number: LP-AM243
Other Parts Discussed in Thread: TUSB320LAI

The power supply error light is continuously lit up (red) when power supply is plugged in. I am using a walwart rated at 5V 3A. Is there a special power supply that you need to operate the device?

  • 0
    TI__Mastermind 22925 points

    Hi Dylan,

    Just to confirm, your power supply is a USB Type C plug and you are plugging this into the USB Type C receptacle on the LaunchPad?  Note that the LP-AM243 is different from previous microcontroller LaunchPads released from TI in that it uses a separate USB Type C connection for powering the board versus the USB Micro B connection that is ONLY used for the XDS110 interface.  So to power the board, you will need a 5V 3A USB Type C supply connected, and the program/debug the board, you will need a USB Micro cable to a host PC running CCS or similar.

  • 0 in reply to Mike Pridgen
    Intellectual 320 points

    Yeah I have the USB Type C power supply adaptor and the USB Micro plugged in. Here is an amazon link to the exact supply used, its a pretty standard one used for things like rpi. With both plugged in the LD11 is on and green, and the LD9 error LED is on and red.

    https://www.amazon.com/gp/product/B07TSDJSQH/ref=ppx_yo_dt_b_asin_image_o08_s00?ie=UTF8&psc=1

  • +1 in reply to Dylan Tarter
    TI__Mastermind 22925 points

    Hi Dylan,

    Thanks for the additional details, those are helpful.  LD11 is controlled by the XDS110, so it being lit green indicates the XDS110 is connected to a host and enumerated correctly.  However, LD9 indicates there is a problem with the USB Type C power source.  The cathode side of LD9 is controlled by the logical OR of the OUT1 and OUT2 signals of the TUSB320LAI USB Type C port controller per the table below, so that if either signal is high , LD9 turns on.

    Based on this, I suspect your power supply is not adequately negotiating the 5V 3A power over the USB Type C connection.  You can measure the TUSB_OUT1 and TUSB_OUT2 signals to see which signal is high, which will indicate what the exact negotiated current state is, but that doesn't really help you.  Your best bet is try a different power supply with your LaunchPad (preferably one that is known to be working with a LP-AM243) or a new LaunchPad with your power supply.  This will let you know if the issue is with your power supply or the LaunchPad itself.

    The LaunchPad User's Guide mentions that this power supply is known to work with the LP-AM243:  https://www.belkin.com/us/chargers/wall/boost-charge-usb-c-pd-3-0-pps-wall-charger-25w/p/p-wca004/.

    As a side note, reading some of the review on Amazon of the power supply you linked, it looks like there are concerns that the unit does not actually supply the full 5V 3A advertised.  I strongly suspect your issue is related to the power supply and if you replace the power supply with one that is actually capable of negotiating and meeting the 5V 3A power requirements, your issues will go away.

  • 0 in reply to Mike Pridgen
    Intellectual 320 points

    Thanks I'll look into getting that power supply, this one is just one that I had on hand from previous projects.