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ADS5400-SP: Is thermal pad internally connected to AGND or DGND of device?

Part Number: ADS5400-SP

Hi experts!

My customer wants to confirm how the thermal pad on the ADS5400-SP is internally connected.

Regarding the guidance to connect the pad to AGND, they have the following questions:

  • Is the AGND or DGND electrically connected to bottom of the package ground inside the ADC package?
  • What are the electrical requirements for the attachment?
  • What is the recommended maximum resistance between the package and the board?
  • How important is the package attachment to board ground to meet ADC performance requirement?


Jim B

  • Hi Jim,

    This is definitely the most important ground connection for any HSADC to sufficiently allow proper return currents, minimize loop inductance and provide a good thermal path.

    The ADC package bottom slug should be connected to AGND. It is recommended to have only a single ground for the system board. There is no need to split ground planes.

    In the case of this package, the requirements for the ground/heat slug opening on the pcb should be the same size as the package outline. This outline should be divided up into several sub-sections on the pcb layout pattern, in order to get adequate coverage during the re-flow process. 

    There is no recommended max resistance conditions, however, if the recommendation is followed above this will be minimized, and a robust ground and thermal path will be developed.

    Hope this helps.