For this example, follow these guidelines:

• Isolate inputs and outputs using a GND shield. Figure 9-6 routes all inputs and outputs as differential pairs.
• Isolate outputs to adjacent outputs when generating multiple frequencies.
• Isolate the crystal area, connect the GND pads of the crystal package and flood the adjacent area. Figure 9-7 shows a foot print which supports multiple crystal sizes.
• Try to avoid impedance jumps in the fan-in and fan-out areas when possible.
• Use five VIAs to connect the thermal pad to a solid GND plane. Full-through VIAs are preferred.
• Place decoupling capacitors with small capacitance values very close to the supply pins. Try to place them very close on the same layer or directly on the backside layer. Larger values can be placed more far away. Figure 9-7 shows three de-coupling capacitors close to the device. Ferrite beads are recommended to isolate the different frequency domains and the VDDVCO domain.
• Preferably use multiple VIAs to connect wide supply traces to the respective power planes.