DS42BR400_07 Datasheet, PDF (1/12 Pages) National Semiconductor (TI) – Quad 4.25 Gbps CML Transceiver with Transmit De-Emphasis and Receive Equalization

December 7, 2007
DS42BR400
Quad 4.25 Gbps CML Transceiver with Transmit De-
Emphasis and Receive Equalization
General Description
The DS42BR400 is a quad 250 Mbps – 4.25 Gbps CML
transceiver, or 8-channel buffer, for use in XAUI Fibre Chan-
nel backplane and cable applications. With operation down to
250 Mbps, the DS42BR400 can be used in applications re-
quiring both low and high frequency data rates. Each input
stage has a fixed equalizer to reduce ISI distortion from board
traces. The equalizers are grouped in fours and are enabled
through two control pins. These control pins provide cus-
tomers flexibility in XAUI applications where ISI distortion may
vary from one direction to another.
All output drivers have four selectable steps of de-emphasis
to compensate against transmission loss across long FR4
backplanes. The de-emphasis blocks are also grouped in
fours. In addition, the DS42BR400 also has loopback control
capability on four channels. All CML drivers and receivers are
internally terminated with 50Ω pull-up resistors.
Features
■ ^{250 Mbps – 4.25 Gbps Fully Differential Data Paths}
■ ^{Optional Fixed Input Equalization}
■ ^{Selectable Output De-emphasis}
■ ^{Individual Loopback Controls}
■ ^{On-chip Termination}
■ ^{Lead-less eLLP-60 pin package (9mmx9mm)}
■ ^{−40°C to +85°C Industrial Temperature Range}
■ ^{6 kV ESD Rating, HBM}
Applications
■ ^{Backplane driver or cable driver}
■ ^{Signal repeating, buffering and conditioning applications}
■ ^XAUI
Functional Block Diagram
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