LILY-W1 series - System integration manual
UBX-15027600 - R09
Design-in
Page 29 of 64
C1 - Public
⚠
If the PD-n pin is not properly routed on the host board, it can trigger a module power cycle during
ESD events. It is recommended to include on this line an optional 10 nF capacitor to GND and
100 k
Ω
pull-up resistor to VCC to improve the immunity against ESD events.
2.10
Design-in checklist
2.10.1
Schematic checklist
LILY-W1 module pins are properly numbered and designated on the schematic (including inner
ground pins).
Power supply design complies with the specification.
The power sequence (including
PD-n
signal handling) is properly implemented.
Adequate bypassing is present in front of each power pin.
Each signal group is consistent with its own power rail supply or proper signal translation has
been provided.
Configuration pins are properly set at bootstrap.
SDIO bus includes series resistors and pull-ups.
Unused pins are properly terminated.
A pi-filter is provided in front of each antenna for final matching.
RF co-location additional filters have been considered in the design.
2.10.2
Layout checklist
PCB stack-up and controlled impedance traces follow PCB manufacturer’s recommendation.
All pins are properly connected and the package follows u-blox’s recommendations for pin
design.
Proper clearance has been provided between RF section and digital section.
Proper isolation has been provided between Antennas (RF co-location, diversity or multi-
antenna design).
Bypass capacitors are placed close to the module.
Low impedance power path has been provided to the module.
Controlled impedance traces are properly implemented on the layout (both RF and digital) and
follow PCB manufacturer recommendations.
50
Ω
RF traces and connectors follow the rules in section 2.2.2.
Antenna design has been reviewed by the antenna manufacturer.
Proper grounding has been provided to the module for low impedance return path and heat
sink.
Reference plane skipping has been minimized for high frequency busses.
All traces and planes are routed inside the area defined by the main ground plane.
u-blox has reviewed and approved the PCB
.
13
This is applicable only for end-products based on u-blox reference designs.