• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 1 answer
  • Subscribers 46 subscribers
  • Views 181 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.

ADS125H02: Testing (of digital parts) with only DVDD possible?

nameduser
Prodigy 30 points
Part Number: ADS125H02

Tool/software:

Hello,

I will soon have to test a PCB that includes a ADS125H02. Will the ADC take damage if only DVDD is connected? Can the inputs be left floating or should they be tied to GND in this case (same question for analog supplies)? Is it possible to test SPI communication with the ADC or is it better to not communicate with the ADC without the analog supply voltages?

Thanks for your support.

  • 0
    TI__Guru 52676 points

    Hi nameduser,

    The ADS125H02 has a power-on RESET (POR) that will not trigger until all supplies are established, see below.

    Communication is unavailable until the POR releases, so you will not be able to communicate with the ADC when AVDD and HVDD are unpowered

    -Bryan

  • 0 in reply to Bryan Lizon86
    Prodigy 30 points

    Thanks! Do I interpret it correctly than I can test surrounding ICs just fine then with only a DVDD supply?

  • 0 in reply to nameduser
    TI__Guru 52676 points

    Hi nameduser,

    I am not sure what you are asking, you want to power other components but leave the ADS125H02 unpowered?

    As long as you are not applying powered signals to an unpowered ADC you should be okay. For example, don't drive the SPI signals when DVDD = 0V (or is floating), and don't apply input signals when HVDD = 0V (or is floating)

    -Bryan

  • 0 in reply to Bryan Lizon86
    Prodigy 30 points

    Yes, I want to power other components that share the DVDD with the ADS125H02. So the ADC would be partially powered in this case. So the setup of my use case (powered DVDD, unpowerded AVDD and HV_AVSS and HV_AVDD) will not cause harm as long as I don't apply an input signal?

    Thanks

  • +1 in reply to nameduser
    TI__Guru 52676 points

    Hi nameduser,

    Understood. The basic guidance for you is to ensure that there are no signals being applied to any unpowered domains (AVDD, HVDD, DVDD). You can send SPI signals to the ADS125H02 if DVDD is powered and there should be no issue. You will just not get any response from the ADC

    -Bryan