ADS8598H: Grounding

Hello Mateo,

To achieve the performance specified in ADC's datasheet, it is important to have a clean and low impedance ground plane and path. Also, sensitive analog circuits should be kept away from noisy digital circuits, a single joint point is recommended for single ADC or multiple devices if a split ground plane is used. These are general principles and there is no a very simple method for a system grounding. As the description in the materials from your link, in some systems, split ground may be used to achieve the performance. In other systems, a single ground plane for both analog and digital circuits is used, and the desired system performance is also achieved, however some customers start out using the split ground approach and later find that the single ground plane gives better performance. Hence, if these principles can be implemented well, the split ground method can be used, otherwise, a single solid ground is recommended. This guideline is suitable for mixed-signal components including ADS8598H, actually the competitor also states a single "AGND" in their similar mixed-signal ADC's datasheet.

I hope these information are helpful for you, thanks.

Best regards

Dale

The datasheet mention that if a single plane cannot be used, the analog and digital plane must be joined. But it means that a grounding technique like the one described cannot be used, because, despite the fact that all points of the ADC are joint together, the analog and digital plane are not connected directly but through the data bus.

thank you very much for your response and patience

And that way I can Keep System Analog and digital planes separate (joint together just through the data bus )?

Hi Mateo,
I'm not sure how you connect the ground through the data bus, but ADS8598H only has simple AGND pins, so a common Analog ground plane is recommended by using short, low-impedance paths and independent vias. Thanks.

Regards,
Dale