Placement; Trace - Sierra Wireless AirPrime XS1110 Product Technical Specification

Product Technical Specification
Rev 4.0 Jul.20

Placement

Place the decoupling capacitors for VCC close to the module.
•
Place the damping resistors for TX / RX close to the module.
•
Do not place:
in proximity to high-speed digital processing circuitry
•
in proximity to high-current switching power circuitry
•
in proximity to clock sources circuitry
•

Trace

1. USB differential signals should be traced closely and of equal length for better
noise immunity and minimum radiation.
2. Apply the 50 impedance of RF trace for matching RF impedance.
Ω
3. Any right angle turn in trace routing should be done with two 135 degree turns
or an arc turn.
Figure 5-7: Examples of Turns in Trace Routing
It is better to have an independent trace of power source for all components as
shown in the figure below:
Figure 5-8: Examples of Independent Trace
4. It is recommended to route the USB-related line within the inner layer.
42 41113354