ZHCSDC7C July 2014 – June 2017 TUSB8020B
PRODUCTION DATA.
VDD should be implemented as a single power plane, as should VDD33.
TI recommends to use only one board ground plane in the design. This provides the best image plane for signal traces running above the plane. The thermal pad of the TUSB8020B and any of the voltage regulators should be connected to this plane with vias. An earth or chassis ground is only implemented near the USB port connectors on a different plane for EMI and ESD purposes.