Lattice Semiconductor

XPIO 110GXS Data Sheet

8

Driving RX_REF_CK_P/N is only necessary when:

• The transmitter and receiver run at independent data rates

• Line Loopback Mode 1 is active

• Line Loopback Mode 2 is active

Figure 5 shows how a reference clock is input to the XPIO 110GXS using an AC coupling scheme.

Figure 5. CML Output Driver Termination (AC Coupled)

Figure 6. CML Input Receiver (AC Coupled)

50Ω

XPIO 110GXS

External

0.1µF

0.1µF

50Ω

50Ω

50Ω

Zo = 50Ω

50

50

0.1µ

0.1µ

Z0 = 50

External

XPIO

DCFB