ADA4899 IC ground circuit connections

Hi CircuitDeveloper ,

For both single and dual supply operation, it is recommended to connect the exposed pad to the ground. The epad is provided for optimum electrical and thermal performance. This will allow the part to effectively dissipate heat to the ground.

For some layout guidelines, here is a link that may help you: A Practical Guide to High-Speed Printed-Circuit-Board Layout 

You can download available footprints on the Symbols, Footprints & 3D models section at the analog.com website: https://www.analog.com/en/resources/packaging-quality-symbols-footprints/symbols-and-footprints.html. Kindly let me know if this is what you are looking for.

Thanks,

Gio

Thank you for your reply.

From experience can you, or anyone else, tell me if I can connect the "ground paddle" to a heat sink that is not connected to ground?   Could connecting the paddle to an ungrounded heat sink result in unintended noise issues?

Also, if the ground paddle is left "floating" what is the recommended operating conditions?  What issues can I expect if the ground paddle is left floating?

Hi CircuitDeveloper ,

I would recommend following the datasheet guidelines. The parts were characterized and tested with these conditions and if you change those conditions you have to expect changes in behavior, maybe latch up or something that will impact the precision behavior. It is always best to connect the paddle back to ground or the recommended voltage via low resistance path. This not only helps with thermal dissipation, it also keeps the back side of the device at a known potential and provides an amount of electrical shielding. 

Best regards,

Gio

Thank you for your help.   

I have read the relevant parameter information of AD4899-1 IC. I think there are potential risks if you do not follow the official parameter table, so I suggest you operate the model according to the parameter table. If you do not follow the official parameter table, if there is a risk in the product, the engineer needs to bear it. I think this is not a wise choice.

Datasheet :https://www.analog.com/media/en/technical-documentation/data-sheets/ADA4899-1.pdf