11.1.4 Ground
The center ground pad of the device must be solidly connected to the ground plane by using a 3 x 3 grid of vias. These ground vias must surround the perimeter of the pad. One of these ground vias must be in the center pad as close as possible to pins #5 (RFIOP) and #6 (RFION). This Ground via serves as the RF ground return path. Also, there must be a ground via in the center pad as close as possible to pin #25 (VSW). This is the ground return for the PMU.