Crystal layout considerations for WirelessUSB Lp

Question: What are the crystal layout considerations for a WirelessUSB LP based system?

 

Answer:

The crystal layout is best if the following conditions are met:

■ Crystal and radio are on same side of PCB
■ Crystal is placed near the crystal pin on the radio
■ Crystal trace paths are as short as possible
■ Match crystal trace paths for length and parasitic capacitance
■ Avoid vias on crystal traces
■ Isolate the crystal from noise sources