DS25CP104 Datasheet, PDF (1/28 Pages) National Semiconductor (TI) – 3.125 Gbps 4x4 LVDS Crosspoint Switch with Transmit Pre-Emphasis and Receive Equalization

August 2007
DS25CP104
3.125 Gbps 4x4 LVDS Crosspoint Switch with Transmit
Pre-Emphasis and Receive Equalization
General Description
The DS25CP104 is a 3.125 Gbps 4x4 LVDS crosspoint switch
optimized for high-speed signal routing and switching over
lossy FR-4 printed circuit board backplanes and balanced ca-
bles. Fully differential signal paths ensure exceptional signal
integrity and noise immunity. The non-blocking architecture
allows connections of any input to any output or outputs. The
switch configuration can be accomplished via external pins or
the System Management Bus (SMBus) interface.
The DS25CP104 features four levels (Off, Low, Medium,
High) of transmit pre-emphasis (PE) and four levels (Off, Low,
Medium, High) of receive equalization (EQ) settable via the
SMBus interface. Off and Medium PE levels and Off and Low
EQ levels are settable with the external pins. In addition, the
SMBus circuitry enables the loss of signal (LOS) monitors that
can inform a system of the presence of an open inputs con-
dition (e.g. disconnected cable).
Wide input common mode range allows the switch to accept
signals with LVDS, CML and LVPECL levels; the output levels
are LVDS. A very small package footprint requires a minimal
space on the board while the flow-through pinout allows easy
board layout. Each differential input and output is internally
terminated with a 100Ω resistor to lower device insertion and
return losses, reduce component count and further minimize
board space.
Features
■ ^{DC - 3.125 Gbps low jitter, low skew, low power operation}
■ ^{Pin and SMBus configurable, fully differential, non-}
blocking architecture
■ ^{Pin (two levels) and SMBus (four levels) selectable pre-}
emphasis and equalization eliminate ISI jitter
■ ^{Wide Input Common Mode Range enables easy interface}
to CML and LVPECL drivers
■ ^{LOS circuitry detects open inputs fault condition}
■ ^{On-chip 100Ω input and output termination minimizes}
insertion and return losses, reduces component count and
minimizes board space
■ ^{8 kV ESD on LVDS I/O pins protects adjoining}
components
■ ^{Small 6 mm x 6 mm LLP-40 space saving package}
Applications
■ ^{SD/HD/3GHD SDI Routers}
■ ^{OC-48 / STM-16}
■ ^{Fibre Channel (2GFC)}
■ ^{InfiniBand and FireWire}
Typical Application
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