Grass Valley SMS-6000 Series - Manual (Page 21)

1-4
Section 1 — Introduction
Serial Digital Video Routing
The serial digital video matrix is capable of handling signals in the
following formats:
■ 143Mb/s D2 NTSC composite
■
177Mb/s D2 PAL composite
■
270Mb/s D1 component
■ 360Mb/s D1 component
Signal Path
The signal path is differential throughout to optimize waveform symmetry
and reduce crosstalk, which is important for transmission down long
cables.
Inputs
The video inputs are terminated in 75
Ω
.
The serial video signal passes through an input receiver circuit built onto a
plug-in SIMM socket so that extra channels can be added in the field. These
circuits provide equalization for losses, mainly at high frequencies, to serial
video signals which have travelled down long cables. This equalization is
varied automatically to suit the length and type of video cable used.
The circuit then locks an oscillator to re-clock the signal so that the correct
pulse widths and timings are regenerated. The circuit can be set to any of
the standards mentioned above, each input being programmed into the
setup of the system, either at the factory or from a PC using the SMS-6000
Configuration Editor. The phase-locked loop is designed to minimize the
jitter on the signal.
Crosspoints
A single crosspoint chip selects the 16 inputs to the 16 outputs. It is rated to
operate to over 1Gb/s ensuring minimum degradation of edge speeds and
symmetry.
Outputs
The output amplifiers are designed to drive 75
Ω
video cables.