• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 47 subscribers
  • Views 255 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.

ADC128S102: input sequence

David Park
Expert 7140 points

Part Number: ADC128S102

Hi,

In the datasheet of ADC128S102, VA has to ramp up faster than VD.

If input sequence is as below picture, what is the expected issue?

Does circuit have to be changed?

Thanks.

  • +1
    TI__Mastermind 25070 points

    Hello,

    When Vd is greater than Va, by more than 300mV, internal diodes are turned on and redirect current to Va. The source for Va will need to be able to sink this current

    Though the device will likely not be damaged during this time, the device can experience a higher current consumption until the situation is corrected. 

    It is strongly suggest to not ramp up Vd faster than Va. an external diode can be added to the power rail to provide protection, we have various TI precision videos available on the topic, i suggest: Protecting ADC with TVS Diode

    Regards

    Cynthia