The following guidelines should be
followed when designing the layout:
- Place the decoupling capacitors as close to the
VCC pins as possible. Placing the decoupling
capacitors directly underneath the device is
recommended if the board design permits.
- High-speed differential
signals TXnP/TXnN and RXnP/RXnN should be tightly coupled, skew matched, and
impedance controlled.
- Avoid vias on the high-speed differential signals
when possible. When vias must be used, take care to
minimize the via stub, either by transitioning
through most or all layers or by back drilling.
- GND relief can be used (but
is not required) beneath the high-speed differential signal pads to improve
signal integrity by counteracting the pad capacitance.
- Place GND vias directly beneath the device
connecting the GND plane attached to the device to
the GND planes on other layers. This has the added
benefit of improving thermal conductivity from the
device to the board.