Si5345-44-42-D-RM
Rev. 1.0
69
5. In general do not route GND, power planes/traces, or locate components on the other side, below the crystal
GND shield. As an exception if it is absolutely necessary to use the area on the other side of the board for
layout or routing, then place the next reference plane in the stack-up at least two layers away or at least 0.05
inches away. The Si5345 should have all layers underneath the ground shield removed.
Figure 40. 64-pin Si5345 Crystal Layout Recommendations Top Layer (Layer 1)
Figure 41. Zoom View Crystal Shield Layer, Below the Top Layer (Layer 2)
Figure 41 shows the layer that implements the shield underneath the crystal. The shield extends underneath the
entire crystal and the X1 and X2 pins. This layer also has the clock input pins. The clock input pins go to layer 2
using vias to avoid crosstalk. As soon as the clock inputs are on layer 2, they have a ground shield above, below,
and on the sides for protection.