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EVAL-AD4030-24FMCZ: SDO0_FMC High after end conversion

Category: Hardware
Product Number: EVAL-AD4030-24FMCZ

I am currently troubleshooting a single EVAL-AD4030-24FMCZ board with a customized MCU Evaluation Board, using guidance from the AD463x driver library.

  • EVAL-AD4030-24FMCZ board is manually powered with 12V Supply.
  • Signal RST_FMC has a 20k pullup to VADJ.
  • For now, MCU Eval board is using 1 MHz SPI clock to do 1-lane SPI transactions.

The issue I am observing is inactivity from ADC(SDO0_FMC) in conversion mode after powerup [default].

SDO0_FMC stays logic-high throughout each1-lane SPI transactions. BUSY_FMC and all other 1-lane SPI FMC signals (CS, SCK, SDI) appear to be functional.

I have attached a few scope shots as reference with observation summary listed below.

What is reason for inactivity on SDO0_FMC? What can be done to fix this issue?

 

Scope Shot Observations

Setup:

  • CH1 (Yellow): CNV_FMC
  • CH4 (Green): BUSY_FMC
  • CH2 (Blue): SDO0 (going to MCU-MISO)
  • CH3 (Magenta): CS_FMC

 Collected Scope Shot (#1)

  • 1A: Test Conversion then 1st SPI Transaction sequence after Power-Up
    • ADC in Conversion mode by default (per datasheet)
  • 1B: (Closeup) BUSY_FMC responds after CNV_FMC rising edge as expected

Repeated Scope Shot (#2) with CH4 (Green) connected to SCK_FMC instead of BUSY_FMC

  • 2A: 1st SPI Transaction sequence after Power-Up
    • Hi-Pulse ADC-Convert and ADC Read Test
    • No Sdo0-to-MISO activity observed (CH2 stays high)
    • 0xFFFFFFFF read as result
  • 2B: SPI Transaction Closeup (see above)

2B2A1B1A

Top Replies

  • I also tried accessing configurations register SDO0_FMC stays high for read transaction.

    Setup:

    • CH1 (Yellow): SDI_FMC (from MCU-MOSI)
    • CH4 (Green): SCK_FMC
    • CH2 (Blue): SDO0 (going to MCU-MISO)
    • CH3 (Magenta): CS_FMC

    Entered Config Mode and Write SW Reset bits to Address 0x00.

    Few msec later, entered Config Mode and Read Diagnostic Register Address 0x34

      • No Sdo0-to-MISO activity observed (CH2 stays high)
      • 0xFF read as result

    Lastly, tried writing value 0xAA to Scratch Register Pad Register Address 0x0A, then Read Scratch Pad Register Address 0x0A

    • No Sdo0-to-MISO activity observed during read transaction (CH2 stays high)
    • 0xFF read as result

  • Hi  ,

       will contact the product owner and get back to you.

    Regards,

    JC

  • So, after trying a 2nd EVAL-AD4030-24FMCZ board with customized MCU Evaluation Board, the SPI communication sequences (including SW reset sequences) are now functional. The 1st EVAL-AD4030-24FMCZ board was found to be in a damaged state that gradually worsened after each power cycle.

    One key item to note: V Supply Startup curves REF vs. 5V must meet 250 mV criteria (per AD4030 datasheet) to mitigate potential damage.

  • Hi  ,


    Thank you for the update. We will take note of your insight and close the thread. But you can still post another thread if ever you will be encountering another problem.


    Regards,
    Jo