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LP8863-Q1: LP8863-Q1: Recovering from fault state without toggling VDD pin?

Barzan Yosuf
Prodigy 10 points
Part Number: LP8863-Q1


Tool/software:

Hi,

I’m using the LP8863-Q1 LED driver via I²C in a Zynq based embedded system. The initial configuration and LED control works correctly after power on.

However, if I reinitialise the device in software (without power cycling), the LP8863-Q1 immediately enters a fault state. The value read from INTERRUPT_STATUS_2 is consistently 0x1280, indicating:

  • OVERTEMP_FAULT

  • BOOST_FAULT

  • LED_OPEN_FAULT_CH2

I’ve tried clearing the faults by writing 0xFFFF to INTERRUPT_STATUS_2, but the same fault reappears on every subsequent initialisation attempt. The device only recovers after a full power cycle.

Could you please clarify:

  1. Is there a recommended soft reset or shutdown sequence to safely reconfigure the device without power cycling?

  2. Does the LP8863-Q1 require disabling outputs or the boost stage before reapplying configuration?

  3. Is toggling the VDD pin the only supported method to fully reset the device?

Any guidance on this subject is much appreciated!

Many Thanks

  • 0
    TI__Mastermind 31831 points

    Dear Sir,

    Thanks for reaching out! Our expert will get back to you soon. Thank you!

    BRs

    Lucia

  • 0
    TI__Mastermind 32605 points

    Hi, Barzan

    A quick question here that what you did on your reinitialise, sounds like something setup is wrong during the test.

    1. Is there a recommended soft reset or shutdown sequence to safely reconfigure the device without power cycling?

      Pls consider disable EN and then change the setup.

    2. Does the LP8863-Q1 require disabling outputs or the boost stage before reapplying configuration?

      We recommend to pull down EN and then change the setup.

    3. Is toggling the VDD pin the only supported method to fully reset the device?

      Yes, VDD toggling is used for reset the device.
  • 0 in reply to Zhiqian Wu
    Prodigy 10 points

    Hi, Thank you for your response. So what I meant by reinitialising the LED chip is that, when the chip is reinitialised without power cycling, the Interrupt_status_2 register raises the following fault flags:

    • LED2_FAULT (Bit 12)
    • OPEN_LED (Bit 9)
    • LED_STATUS (Bit 7)
    However, when checking the status of the FSM, it shows as NORMAL. Based on this, the fault flags set on the second initialisation of the chip may not have been a latch faults hence the device carried on working as NORMAL despite the flags. I understand that the flags will always be there by design unless the VDD is toggled. 
  • 0 in reply to Barzan Yosuf
    TI__Mastermind 32605 points

    Hi, Barzan

    Pls kindly give me your initial item. Depending on your register, LED2 see open fault, I want to know what you did.