• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 46 subscribers
  • Views 194 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.

ADS1299: Power Loss

Mark Smith2
Prodigy 20 points
Part Number: ADS1299

One thing the datasheet doesn't mention is what happens in the case of a full or partial power loss. The absolute maximums of the Analog and Digital supplies don't seem to reference each other, but does the digital side keep on trucking if the analog side goes down? And of course, what happens with the reverse situation, if the digital side drops?

I guess the question really is, if I pull a battery is something going to break?

  • 0
    TI__Guru 55152 points

    Hi Mark,

    In a full or partial power loss I would expect the device to no longer adhere to the specified level of performance. Depending on the exact nature of the power loss, more than likely it will "lock up" and require a full reset to continue working. If the digital side goes down, then there's nothing to output data, if the analog side goes down, there's nothing to sample the data. Either way, the flow will stop. 

    I would not expect something to break if the battery is pulled properly, but it's certainly possible that a transient event occurs that could be damaging. 

  • 0 in reply to Alexander Smith
    Prodigy 20 points

    Hi Alex,

    Thanks for the response! Unfortunately I'm still unclear on the correct way to handle this. Given that the analog and digital sides of the chip are likely to be powered with separate supplies, what is the correct power down procedure to ensure the chip is not damaged? And when you say transient, are you referring to short pulses/contact bounces, or something like static due to handling? Is this something I should be running through a PMIC?

  • 0 in reply to Mark Smith2
    TI__Guru 55152 points

    Hi Mark,

    Happy to help! 

    The supplies should be separate through some sort of regulation in order to keep the noise from coupling into the other supply. As long as the voltage applied stays within the absolute maximum ratings of the device, it will not be damaged.

    Yes, short time, high voltage magnitude pulses. Static due to handling is certainly a concern, I recommend using tweezers to make sure you're not shorting pins with your fingers/static shocking the device, an ESD strap, and an ESD safe work surface. If you're pulling a battery and there's an un-intentional short that creates an arc that reaches the device it will certainly be a concern as well. 

    I believe PMICs are intended for processors. A couple LDO's/regulators (one for each supply) is most likely all that the ADS1299 will need, however I'm not sure about the battery. I'm not specialized in power management so posting on the battery management/LDO/regulator forum may yield a more concrete response.

    I also recommend taking a look at the ADS1299EEGFE-PDK User's Guide for an example schematic.