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DAC81401: Help with DAC81401 Evaluation Module Setup and Power Issue

Thiemo Baumann
Prodigy 10 points

Part Number: DAC81401

Tool/software:

Hello,

I recently purchased the DAC81401 Evaluation Module. Unfortunately, when I attempted to power up the module, something went wrong. I had initially set the jumpers following the layout shown in “Figure 3-2. Default Header Settings with High Voltage Gain Stage Disabled” on page 11 of the datasheet. However, I didn’t realize that this configuration wasn’t intended for external biasing. It seems I may have made an error here.

When I powered the module under these settings, I noticed a current draw of around 70mA at both +5V and -5V for all biases, except the high-voltage one, which i didn't connect. After adjusting the jumpers correctly and connecting only the power supplies to DVDD (J6), AVDD (J3), and AVSS (J4)—each set to either +5V or -5V—the biasing current has now dropped to 1mA on both channels of the power supply. This current level seems somewhat low to me.

When I attempt to use the software to control the board, I’m not seeing any response from the board pins when changing the registers. I’m concerned that one of the chips may have been damaged in the process.

Any guidance or insights you could provide would be greatly appreciated.

Kind regards,
Thiemo

  • 0
    TI__Expert 6400 points

    Hi Thiemo,

    Device getting damages is not expected. To debug if there is any issue on the EVM, please follow the instructions given below and provide the details as requested in each step. 

    Follow the below setting for power supplies

    • AVDD : +12V
    • AVSS : 0V > J2 setting
    • DVDD : 5V > J1 use 5V onboard power supply 
    • IOVDD : 3.3V > onboard setting
    • EXT HV POS (V+) & EXT HV NEG : leave it floating

    Measure the voltage levels and make sure that it's good.

    Next step, use the GUI and follow the instructions provided in the user's guide in the section 3.3 Setup. Write the SPI commands one by one and monitor the digitals signals on J12. And confirm the following details - 
     
    1. Measured supply voltages on the EVM
    2. Are you able to bring up the internal reference voltage and/or DAC OUT voltage on the EVM? If yes, what are the measured values ? 
    3. If no, are you getting the SPI digital signals on the J12 connector pins?
     
    Thanks,
    Sanjay