SPRS975H August 2016 – February 2020 DRA780 , DRA781 , DRA782 , DRA783 , DRA785 , DRA786 , DRA787 , DRA788
Refer to the PDF data sheet for device specific package drawings
The PCB stack-up (layer assignment) is an important factor in determining the optimal performance of the power distribution system. An optimized PCB stack-up for higher power integrity performance can be achieved by following these recommendations:
1-2oz Cu weight for power / ground plane is preferred to enable better PCB heat spreading, helping to reduce Processor junction temperatures. In addition, it is preferable to have the power / ground planes be adjacent to the PCB surface on which the Processor is mounted.
The placement of power and ground planes in the PCB stackup (determined by layer assignment) has a significant impact on the parasitic inductances of power current path as shown in Figure 7-1. For this reason, it is recommended to consider layer order in the early stages of the PCB PDN design cycle, putting high-priority supplies in the top half of the stackup (assuming high load and priority components are mounted on the top-side of PCB) and low-priority supplies in the bottom half of the stackup as shown in the examples below (vias have parasitic inductances which impact the bottom layers more, so it is advised to put the sensitive and high-priority power supplies on the top/same layers).