DS25MB200_08 Datasheet, PDF (1/14 Pages) National Semiconductor (TI) – Dual 2.5 Gbps 2:1/1:2 CML Mux/Buffer with Transmit Pre- Emphasis and Receive Equalization

April 9, 2008
DS25MB200
Dual 2.5 Gbps 2:1/1:2 CML Mux/Buffer with Transmit Pre-
Emphasis and Receive Equalization
General Description
The DS25MB200 is a dual signal conditioning 2:1 multiplexer
and 1:2 fan-out buffer designed for use in backplane redun-
dancy applications. Signal conditioning features include input
equalization and programmable output pre-emphasis that en-
able data communication in FR4 backplanes up to 2.5 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 sys-
tem testing. All receiver inputs are internally terminated with
100Ω differential terminating resistors. All drivers are inter-
nally terminated with 50Ω to V_CC.
Features
■ ^{0.6–2.5 Gbps low jitter operation}
■ ^{Fixed input equalization}
■ ^{Programmable output pre-emphasis}
■ ^{Independent switch and line side pre-emphasis controls}
■ ^{Programmable switch-side loopback modes}
■ ^{On-chip terminations}
■ ^{HBM ESD rating 6 kV on all pins}
■ ^{+3.3V supply}
■ ^{Lead-less LLP-48 package (7mm x 7mm x 0.8mm, 0.5mm}
pitch)
■ ^{—40°C to +85°C operating temperature range}
Applications
■ ^{Backplane or cable driver}
■ ^{Redundancy and signal conditioning applications}
Functional Block Diagram
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