1FEATURES
2• 1– 4.25 Gbps Fully Differential Data Paths
• Fixed Input Equalization
• Programmable Output Pre-emphasis
• Independent Switch and Line Side Pre-
emphasis Controls
• Programmable Switch-side Loopback Mode
• On-chip Terminations
• +3.3V Dupply
• ESD Rating HBM 6 kV
• Lead-less WQFN-48 Package
(7mmx7mmx0.8mm, 0.5mm Pitch)
• –40°C to +85°C Operating Temperature Range

APPLICATIONS
• Backplane Driver or Cable Driver
• Redundancy and Signal Conditioning
Applications
• XAUI

DESCRIPTION
The DS42MB200 is a dual signal conditioning 2:1
multiplexer and 1:2 fan-out buffer designed for use in
backplane redundancy applications. Signal
conditioning features include input equalization and
programmable output pre-emphasis that enable data
communication in FR4 backplanes up to 4.25 Gbps.
Each input stage has a fixed equalizer to reduce ISI
distortion from board traces.
All output drivers have 4 selectable steps of pre-
emphasis to compensate for transmission losses from
long FR4 backplanes and reduce deterministic jitter.
The pre-emphasis levels can be independently
controlled for the line-side and switch-side drivers.
The internal loopback paths from switch-side input to
switch-side output enable at-speed system testing. All
receiver inputs are internally terminated with 100Ω
differential terminating resistors. All driver outputs are
internally terminated with 50Ω to VCC.