Document Number: 001-07425 Rev. ** Page 4 of 9
Equalizer Operation
The CYV15G0104EQ is a high speed adaptive cable equ alizer
designed to equalize standard definition (SD) and high definition
(HD) serial digital interface (SDI) video data streams..The
CYV15G0104EQ equal izer is optimized to equalize up to 350 m
of Belden 1694A cable and Canare L-5C FB cable at 270 Mbps
and typically up to 200m of Belden 1694A cable and Canare
L-5CFB cable at 1.485 Gbps. The CYV15G0104EQ equalizer
contains one power supply and typically consumes 160 mW
power at 3.3V. The multi rate equalizer meets the SMP TE 259M,
SMPTE 292M, SMPTE 344M, and DVB-ASI vi deo standards. It
meets all pathological requirements for SMPTE 292M as defined
by RP198 and for SMPTE 259M as defined by RP178. The
CYV15G0104EQ multi rate cable equalizer operates from 143
Mbps to 1.485 Gbps serial data rate.
The CYV15G0104EQ equalizer has multiple variable gain equal-
ization stages that reverse the attenuation 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 CYV15G0104EQ has DC restoration to
compensate for the DC content of the SMPTE pathological
patterns.
SDI, SDI
CYV15G0104EQ accepts single-ended or differential serial
video data streams over 75Ω coaxia l cable. It is recommended
to AC couple the SDI, SDI input s as th ey are in ternally biased t o
1.2V.
SDO, SDO
The CYV15G0104EQ 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 HOTLink II receivers.
MCLADJ
Maximum Cable Length Adjust (MCLADJ) sets the approximate
maximum amount of cable to be equalized. When the maximum
cable length set by MCLADJ is reached, the CD pin is
deasserted. To enable automatic muting of the device upon loss
of signal, C D should be tied directly to MUTE. MCLADJ works at
SD and HD data rates.
Figure 2 on page 7 illustrates the voltage required at MCLADJ
input to equalize various Belden 1694A cable lengths. If
MCLADJ functionality is not required, this pin should be left
floating or tied to ground to enable maximum equalized cable
length.
MUTE
MUTE is an input pin that controls the muting of the equalizer ’s
output. MUTE operates for both HD and SD data rates.
If MUTE is set LOW, the equalizer serial outputs are not muted.
If MUTE is set HIGH, then the equalizer serial outputs are muted.
When MUTE is active, BYPASS setting is also ignored.
Connecting CD to MUTE pin enables automatic muting of the
equalizer upon loss of signal.
Do not leave the MUTE pin floating. Always drive it to a known
state.
Carrier Detect (CD)
Carrier Detect is an active LOW output pin that indicates the
presence of a valid incoming data signal. When the incoming
data signal is present, and maximum cable length does not
exceed that set by MCLADJ, CD outputs a voltage less than
0.8V.
When the incoming data stream is not present, or maximum
cable length exceeds that set by MCLADJ, CD outputs a voltage
greater than 2.8V.
Connecting CD to MUTE pin enables automatic muting of the
equalizer upon loss of signal.
BYPASS
The CYV15G0104EQ has a bypass mode that enables the user
to bypass the equalizer’s equalization and DC restoration
functions. When BYPASS 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 equal-
izing.
When BYPASS is set LOW, the incoming video data stream is
equalized and presented at the equalizer‘s differential serial
outputs (SDO, SDO).
AGC
Place a capacitor of 1 μF between the AGC and AGC pins of the
CYV15G0104EQ equalizer
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