NINA-B50 series - Hardware integration manual
UBX-22021116 - R02
Design-in
Page 27 of 57
C1-Public
3.3.3
Layout and manufacturing
•
Avoid stubs on high-speed signals which might adversely affect signal quality. Test points or
component pads should be placed over the PCB trace.
•
Verify the recommended maximum signal skew for differential pairs and length matching of
buses.
•
Minimize the routing length. Ensure that the maximum allowable length for high-speed buses is
not exceeded. Longer traces generally degrade signal performance.
•
For impedance matched traces, consult with your PCB manufacturer early in the project for proper
stack-up definition.
•
Separate the RF and digital sections of the board.
•
Don’t split g
round layers under the module.
•
Minimize the routing length. Ensure that the maximum allowable length for high-speed buses is
not exceeded. Longer traces generally degrade signal performance.
•
Couple all traces (including low speed or DC traces) with a reference plane (GND or power), and
reference all hi-speed buses against the ground plane. If any ground reference needs to be
changed, add an adequate number of GND vias in the area in which the layer is switched. This is
necessary to provide a low impedance path between the two GND layers for the return current.
•
Don’t change the reference plane for
Hi-Speed buses. If changes in the reference plane are
unavoidable, add capacitors in the transition area of the reference planes. This is necessary to
ensure that a low impedance return path exists through the different reference planes.
•
Following the “3w rule”, keep traces at a distance no less than three times that of its own width
from the routing edge of the ground plane.
•
For EMC purposes and the need to shield against any potential radiation, it is advisable to add
GND stitching vias around the edge of the PCB. Traces on the PCB peripheral are not
recommended.
3.4
Module footprint and paste mask
shows the pin layout of NINA-B501 module. The proposed land pattern layout complements
the pin layout of the module. Both Solder Mask Defined (SMD) and Non Solder Mask Defined (NSMD)
pins can be used
–
with adherence to the following considerations:
•
All pins should be Non-Solder Mask Defined (NSMD)
•
To help with the dissipation of the heat generated by the module, GND pads must have good
thermal bonding to PCB ground planes.
