DS25BR400_08 Datasheet, PDF (1/14 Pages) National Semiconductor (TI) – Quad 2.5 Gbps CML Transceiver with Transmit De-Emphasis and Receive Equalization

March 21, 2008
DS25BR400
Quad 2.5 Gbps CML Transceiver with Transmit
De-Emphasis and Receive Equalization
General Description
The DS25BR400 is a quad 250 Mbps – 2.5 Gbps CML
transceiver, or 8-channel buffer, for use in backplane and ca-
ble 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 con-
trol 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 trans-
mission 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.
Features
■ ^{250 Mbps – 2.5 Gbps low jitter operation}
■ ^{Optional Fixed Input Equalization}
■ ^{Selectable Output De-emphasis}
■ ^{Individual Loopback Controls}
■ ^{On-chip Termination}
■ ^{+3.3V supply}
■ ^{Lead-less eLLP-60 pin package}
(9mmx9mmx0.8mm, 0.5mm pitch)
■ ^{−40°C to +85°C Industrial Temperature Range}
■ ^{6 kV ESD Rating, HBM}
Applications
■ ^{Backplane or cable driver}
■ ^{Signal buffering and repeating}
Simplified Application Diagram
20194240
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