DS25BR400,pdf datasheet (Quad

The DS25BR400 is a quad 250 Mbps – 2.5 Gbps CML
transceiver, or 8-channel buffer, for use in backplane and cable
applications. With operation down to 250 Mbps, the
DS25BR400 can be used in applications requiring both low
and high frequency data rates. Each input stage has a fixed
equalizer to reduce ISI distortion from board traces. The
equalizers are enabled through two control pins. These control
pins provide flexibility in applications where ISI distortion
may vary from one direction to another. All output drivers have
four selectable steps of de-emphasis to compensate for transmission
loss. The de-emphasis blocks are also grouped in
fours. In addition, the DS25BR400 also has loopback control
capability on four channels. All the CML drivers have 50Ω
termination to Vcc. All receivers are internally terminated with
differential 100Ω.