AD7915 - Connection of VDD bypass caps to AGND or DGND?

From customer:

I am planning to have independent AGND and DGND ground planes in my system, and plan to short the two GNDs together at or under the ADC.

If I use the AD7915, would the bypass capacitors for VDD (2.5V power rail for ADC core) be connected to AGND or DGND?

Initially I would have thought it would attach to DGND, since it drives the ADC SAR structures and likely has some high-frequency digital content.

But I noticed in one of the packages that the VDD pin is placed right next to the analog IN+/- pins, and I know the pin layouts on these ADCs is derived to allow a AGND/DGND split across the part body center. This seems to imply that it would be better to bypass VDD to AGND…

Parents
  • 0
    •  Analog Employees 
    on Aug 2, 2018 3:28 PM
    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

    Thank you,
    EZ Admin
Reply
  • 0
    •  Analog Employees 
    on Aug 2, 2018 3:28 PM
    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

    Thank you,
    EZ Admin
Children
No Data