• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 46 subscribers
  • Views 85 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.

DAC8562: Internal connection circuit for Digital inputs CLR, DIN, LDAC, SCLK and SYNC

Athun Siva
Prodigy 20 points
Part Number: DAC8562

Tool/software:

Hi TI Support team, 

I have connected AVDD with 3.3V supply and a separate one (3.3V Digital) pullup supply to all Digital inputs CLR, DIN, LDAC, SCLK and SYNC.

I would like to analyze the scenario when only pull up voltage is enabled and not the AVDD. I observed a drop across the pull up resistor reducing the pin voltage lesser when the AVDD is not ON. Is it because there is current sink due to the IC internal circuit connection. Can this cause a reliability issue and damage the IC?

I do need to evaluate this since both of the supply's are coming from another external board and there could be instances where both are not Powered ON at the same time.

  • 0
    TI__Mastermind 41903 points

    Hi Athun, 

    This condition is violating the absolute maximum ratings of the part. The max voltage on any pin must be limited to AVDD + 0.3V which you are violating by powering on the digital input pins before AVDD. The internal ESD diodes are being activated during this condition which is why you are seeing a drop across the resistor. 

    Best,

    Katlynne Jones