When designing the Printed Circuit Board (PCB) layout, interface-specific
recommendations should be followed.
The Universal Integrated Circuit Card (UICC) interface has the following recommendations:
- If the product integrates a Global Positioning System (GPS) or LTE antenna, avoid placing
the Subscriber Identity Module (SIM) holder close to the antenna due to the risk of digital
noise coupling from the SIM application to the antenna.
- Place the UICC application as close to nRF9160 as possible to minimize the routing length.
Long routing reduces signal integrity in the UICC interface and increases the risk of radiated
noise.
- Use the same application board ground plane for the UICC application and nRF9160's
VSS to guarantee low impedance ground connection between nRF9160 and the
UICC application.
- Avoid routing the UICC interface close or adjacent to sensitive RF routings, such as GPS or
ANT.
- Place the Electrostatic Discharge (ESD) and EMI components or discrete components as close
as possible to the UICC application's pins SIM_RST,
SIM_CLK, SIM_IO, and SIM_1V8 to
optimize their performance.
- Consider test points in SIM_RST, SIM_CLK, and
SIM_IO for debugging purposes.