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DS90UB913A-Q1: DS90UB913 and DS90UB914 DAP connection to GND- there are conflicting instructions in the datasheet

Z78M12
Prodigy 85 points
Part Number: DS90UB913A-Q1
Other Parts Discussed in Thread: DS90UB913A-CXEVM, DS90UB914A-CXEVM

Hi,

We about to end the layout this week and the layout person just highlight something regarding thermal pad connection, so we need your feedback ASAP.

In DS90UB913 datasheet page 7 under pin name VSS is says:  "Connected to the ground plane (GND) with at least 9 vias".
On page 55 there is an example of the board layout and land pattern example. But over there you show only 5 vias recommendation.
DS90UB913A-CXEVM brd file use 9 vias.


So my question: how many vias we should use for the 913  DAP connection in the layout?


The same for DS90UB914:
In the datasheet page 8 under pin VSS is says: "Connected to the ground plane (GND) with at least 16 vias"
On page 59 there is an example of via and opening placement. You use 9 vias (also the DS90UB914A-CXEVM BRD file includes only 9 vias).

So again: how many vias we should use for the 914 DAP connection in the layout?

  • +1
    TI__Mastermind 18755 points

    Hi,

    The datasheet specifies how many vias are needed in the table you mentioned, the drawings are specific to the package and may not show all required vias but define via spacing instead.  The package defined in the datasheet may be used for other parts as well and is a more generic drawing where the datasheet calls out the amount of vias required for the actual part.

    Regards,

    Nick