CYV15G0100EQ
Document Number: 001-12520 Rev. **
Page 4 of 10
Equalizer Operation
The CYV15G0100EQ is a high speed adaptive cable equalizer
designed to equalize standard definition (SD) and high definition
(HD) serial digital interface (SDI) video data streams. The
CYV15G0100EQ equalizer is optimized to equalize up to 175m
of Canare L-5CFB and Belden 1694A cable
at 270 Mbps and up
to 70m of Canare L-5CFB and Belden 1694A cable at 1.485
Gbps. The CYV15G0100EQ equalizer contains one power
supply and typically consumes 160 mW power at 3.3V. The multi
rate equalizer meets the SMPTE 259M, SMPTE 292M, SMPTE
344M, and DVB-ASI video standards. It meets all pathological
requirements for SMPTE 292M as defined by RP198 and for
SMPTE 259M as defined by RP178. The CYV15G0100EQ
Prosumer video cable equalizer is auto adaptive from 143 Mbps
to 1.485 Gbps.
The CYV15G0100EQ equalizer has variable gain and multiple
equalization stages that reverse the effects of the cable. This
equalization is achieved by separate regulation of the lower and
higher frequency components in the signal to give a clean output
eye diagram. The CYV15G0100EQ has DC restoration for
compensating the DC content of the SMPTE pathological
patterns.
SDI, SDI
The CYV15G0100EQ accepts single-ended or differential serial
video data streams over 75
Ω
coaxial cable. It is recommended
to AC couple the SDI and SDI inputs as they are internally biased
to 1.2V.
SDO, SDO
The CYV15G0100EQ has differential serial output interface
drivers that use current mode logic (CML) drivers to provide
source matching for the transmission line. These outputs are
either AC coupled or DC coupled to the HOTLink II SerDes
device.
CLI
Cable Length Indicator (CLI) is an analog output that gives an
output voltage proportional to the equalized cable length. CLI
gives an approximation of the length of cable at the differential
serial inputs (SDI, SDI). CLI works at high definition (HD) data
rates and standard definition (SD) data rates. The graph in
Figure 3
on page 7 illustrates the CLI output voltage at various
Belden 1694A cable lengths. With an increase in cable length,
CLI output voltage decreases.
MCLADJ
Maximum Cable Length Adjust (MCLADJ) sets the approximate
maximum amount of cable to be equalized. MCLADJ works at
SD and HD data rates.
If the MCLADJ voltage is greater than the CLI output voltage, the
CD pin is driven HIGH
and the outputs are muted. If the MCLADJ
voltage is less than CLI voltage, then the equalizer’s CD pin is
driven LOW and the incoming data stream is equalized. The
graph in
Figure 2
on page 7 illustrates the voltage required at
MCLADJ input to equalize various Belden 1694A cable lengths
for SD and HD data rates.
If MCLADJ functionality is not needed, then this pin should be left
floating or tied to ground to allow maximum equalized cable
length.
CD/MUTE
Carrier Detect/MUTE (CD/MUTE) is a bidirectional pin that
provides an indication of the signal present at the equalizer’s
input or it controls the muting of the equalizer’s output. The
(CD/MUTE) operates for both HD and SD data rates.
If CD/MUTE is used as an output and the incoming data stream
is not present or the cable length exceeds the length that is set
by MCLADJ, the voltage at the CD/MUTE output is greater than
2.8V. If CD/MUTE is used as an output, the incoming data stream
is present and the cable length does not exceed the length that
is set by MCLADJ, then the voltage at the CD/MUTE output is
less than 0.8V.
If CD/MUTE is used as an input and is set LOW, the equalizer
serial outputs are not muted. If the CD/MUTE is used as an input
and is set HIGH, then the equalizer serial outputs are muted.
When an invalid signal or a signal transmitted with a launch
amplitude of less than 500 mV at HD data rates is received, the
equalizer’s serial outputs are muted.
BYPASS
The CYV15G0100EQ has a bypass mode that enables the user
to bypass the equalizer’s equalization and DC restoration
functions. When the bypass mode is set HIGH, the signal
presented at the equalizer’s differential serial inputs (SDI, SDI)
is routed to the equalizer’s differential serial outputs (SDO, SDO)
without equalizing.
When BYPASS is set LOW, the incoming video data stream is
equalized and presented at the equalizer‘s differential serial
outputs (SDO, SDO).
In equalizer bypass mode, CD/MUTE is not functional.
AGC
Place a capacitor of 1
μ
F between the AGC± pins of the
CYV15G0100EQ equalizer.
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