DS42BR400_08 Datasheet, PDF (1/14 Pages) National Semiconductor (TI) – Quad 4.25 Gbps CML Transceiver with Transmit De-Emphasis and Receive Equalization

March 27, 2008
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 backplane and ca-
ble applications. With operation down to 250 Mbps, the
DS42BR400 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 grouped in fours and are enabled through two
control pins. These control pins provide customers flexibility
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 have 50Ω termi-
nation to V_CC. All receivers are internally terminated with
differential 100Ω.
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 (9 mm x 9 mm x 0.8 mm,}
0.5 mm pitch)
■ ^{−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}
Simplified Application Diagram
20182440
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