PCB design Guidelines
Schematic Review
-component clearances (>2mm for bigger components and ICs, >0.5mm upto 0805 components. Use 0.25mm placement grids or appropriately
-Place all the connectors as per mechanical, stacking requirement (SMA, SIM, uSD, reset, USB, LAN, headers for LED, PLCIO, Connector PCB, unused signals)
-Place major components considering SI of high speed/RF signals
-Place storage/decoupling capacitors at power entry points of all major components (Load)
-Place PDN components and passives
Review
-Optimise the placements
Review
-Course route of following signals
--RF Signals and Grounding
--USB (90 Ohm)
--MDI of LAN
--RMII of PHY
--uSD
Review
-Decoupling cap placing adj and routing
-Routing of power entry to decap
Review
-Adjust the placements if required
-Complete the planes/wide traces wherever required
-Thermal consideration for heat dissipating comp like LDO, DC-DC (put max. possible copper area)
Review
-Fine routing (adjust placements if required)
-Finish routing
Review
Gerber
Review
Note :
a. The stacking connectors at the opposite end of the edge where SMA USB LAN placed.
b. Provide max. space at the stacking connector to place serial interface components in future