Figure 9-10 through Figure 9-15 show the recommended input interfacing and termination circuits. Unused clock inputs can be left floating or pulled down.
Figure 9-10 Single-Ended LVCMOS (1.8
V, 2.5 V, 3.3 V) to Reference (INx_P) or XO Input
(XO)
Figure 9-11 DC-Coupled LVPECL to Reference (INx)
Figure 9-12 DC-Coupled HSDS/LVDS to
Reference (INx)
Figure 9-13 DC-Coupled CML (Source Terminated) to Reference (INx)
Figure 9-14 HCSL (Load Terminated) to Reference (INx)
Figure 9-15 AC-Coupled Differential to Reference (INx)