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ADS131A04EVM: D3 RED LED

Chinmaya Dash
Prodigy 30 points
Part Number: ADS131A04EVM

Hi,

As I plug in the EVM to my host computer, the D3 LED glows.

The EVM stays in the D3 LED on state for a variable time. Sometimes it quickly moves to "D1 D2 green quickly". Sometimes it takes few minutes before the "D1 D2 green" state.

Is there an explanation of what is happaning?

Regards

Chinmaya

  • 0
    TI__Guru* 94415 points

    Chinmaya,


    I was able to find this post in E2E describing D3 in the ADS131A04EVM:

    e2e.ti.com/.../640433

    In that post, it is mentioned that D3 is used to indicate an issue in the ADS131A04EVM power generation. The post above mentions:

    "The DC Jack and the surrounding voltage regulators are not installed on the EVM, which is where the statement about 'USB power only' on page 16 is coming from. These are the 'DNP' components shown in Figure 12 (page 27) of the users guide. Those DNP components, ultimately provide the 'EXT_5V' shown in the lower left corner of Figure 11 (page 26). The USB isolator you have can only provide 100mA of current which I suspect is not enough to start up the ADS131A04EVM. You should be able to verify this by probing TP3, TP4 and TP5 relative to any of the GND test point. The voltage at TP3 should be 5.5 to 6V. The voltage at TP4 should be 1.8V and the voltage at TP5 should be 5V. Please measure the voltage at these test points and let us know what you find."

    If D3 is coming up RED for significant amounts of time, I would also try removing anything else connected to USB. Because USB is limited in the current it can provide, perhaps something else on the USB bus is drawing enough current to create problems as the EVM is coming up.

    Do you have anything else connected on USB? Is there anything connected to the EVM that may draw current?


    Joseph Wu

  • 0 in reply to Joseph Wu
    Prodigy 30 points

    Hi Joseph,

    Thanks for helping out.

    After reducing connections to USB I am definitely seeing faster power up.

    Also I found out from https://e2e.ti.com/support/data-converters/f/73/t/768279?tisearch=e2e-sitesearch&keymatch=ADS131A04EVM%3A%201-2 that my understanding of default settings for board to work with EVM software could be wrong. I was keeping S4,S5 and S8 as up!

    Is there a complete list / picture that I can refer to for board switch and jumper settings for evm software control.

    Regards

    Chinmaya

  • 0 in reply to Chinmaya Dash
    TI__Guru* 94415 points

    Chinmaya,



    If you look at the EVM User'sGuide:

    www.ti.com/.../sbau259a.pdf,

    The jumper settings shown in Figure 2 should work for the EVM. However, I've collected a couple of errata for this EVM, which does include two switch positions.

    - Silkscreen wrong for S5 (up is buffer, down is header)
    - Silkscreen wrong for S8 (up is buffer, down is header)
    - R89 should not be populated or the U29 buffer will not work
    - MISO and MOSI silkscreens are swapped on J3, pins 3 and 5
    - R90 can be removed. It shouldn't affect operations, but it doesn't need to be pulled down.



    Joseph Wu

  • 0 in reply to Joseph Wu
    Prodigy 30 points

    Hi Joseph,

    The info you gave is very useful.

    I am still trying to make full use of TI's software.

    When I start, sometimes the tool correctly reads registers.

    However most of the times, I see a "Write failed" message at the bottom left corner.

    What is meaning of this message - is it a failure of communication between onboard microcontroller and ADC or is it a failure of communication between software on computer and onboard microcontroller?

    Thanks

    Chinmaya

  • 0 in reply to Chinmaya Dash
    TI__Guru* 94415 points

    Chinmaya,

    Sorry I didn't get back to you, but I was out of the office at the end of last week.

    I don't know if I've seen this error before. Can you get a screen shot of the error and post it back here? Also, can you let me know when this happens? Does it happen mostly at startup or is it at any particular time in the EVM operation?

    I'll see if I can get more information about the "write failed" error message.

    Joseph Wu

  • 0 in reply to Joseph Wu
    TI__Guru* 94415 points

    Chinmaya,

    For this device, the registers are locked unless the user sends the UNLOCK command to this device. The default state would be to have locked registers. If you are starting the device/EVM up or if you have RESET the device, you may need to send the UNLOCK command again.

    Joseph Wu