DS42MB200

Dual 4.25 Gb/s 1:2 Mux/Buffer with Input Equalization

and Output Pre-Emphasis

General Description

The DS42MB200 is a dual signal conditioning 2:1 multi-

plexer and 1:2 fan-out buffer designed for use in backplane

redundancy applications. Signal conditioning features in-

clude input equalization and programmable output pre-

emphasis that enable data communication in FR4 back-

planes up to 4 Gb/s. 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 indepen-

dently 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 and driver outputs are internally terminated with 100

Ω

differential terminating resistors

Features

n

Dual 2:1 multiplexer and 1:2 buffer

n

1– 4.25 Gbps fully differential data paths

n

Fixed input equalization

n

Programmable output pre-emphasis

n

Independent switch and line side pre-emphasis controls

n

Programmable switch-side loopback mode

n

On-chip terminations

n

+3.3V supply

n

Low power, 1W max

n

ESD rating HBM 6 kV

n

Lead-less LLP-48 package (7mmx7mmx0.8mm, 0.5mm

pitch)

n

–40˚C to +85˚C operating temperature range

Functional Block Diagram

20178633

May 2006

© 2006 National Semiconductor Corporation

DS201786

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