M21234 Datasheet, PDF (1/20 Pages) M/A-COM Technology Solutions, Inc. – Adaptive Coaxial Cable Equalizer

M21234 (HD/SD-SDI) Adaptive Coaxial Cable Equalizer
The M21234 is a high-speed, low-power, adaptive co-axial cable equalizer designed to increase the maximum low-
jitter transmission distance of serial digital interface (SDI) video signals and DVB-ASI across commonly used
bandwidth-limiting 75Ω coaxial cable. This device automatically optimizes its transfer function based on the bit rate
and cable length to minimize the inter-symbol interference (ISI) jitter caused by the cable as well as remove the DC
offset components introduced with the pathological test pattern and AC coupling in systems.
The M21234 is designed to support SMPTE (292M) at HD data rates as well as SMPTE (259M and 344M) at SD
data rates between 143 Mbps and 540 Mbps.
The low-noise, high-gain equalizer allows for low jitter (output jitter of 0.25 UI pp @ 1.485 Gbps) HD transmissions
up to a typical cable length of 175m (Belden 1694A) and 130m (Belden 8281). For SD data rates, a typical cable
length of 350m (Belden 1694A) and 275m (Belden 8281) at 270 Mbps SD rate (with typical output jitter of 0.20 UI) is
supported.
Features
• SMPTE/DVB-ASI compliant from 143 to 1485 Mbps operation
• CML, LVPECL and LVDS selectable output modes
• Improved distance: cable EQ up to 350m SD and 175m HD
• Low Power (125 mW @ 1.8V, 175 mW @ 2.5V, 230 mW @ 3.3V)
• Extended Temperature range: -10 to 85 °C
Applications
• SMPTE Coaxial Cable Interface
• Studio video applications
• Broadcast video applications
• Distribution video applications
Standards Compliance
• SMPTE 259M, SMPTE 292M, SMPTE 344M
Functional Block Diagram
EQ_BYP
OUTMODE[1:0]
SDI
INPUT
BUFFER
SDI
1
EQUALIZER
CORE
0
DC
RESTORE
OUTPUT
BUFFER
M21234 Cable Equalizer
CABLE
LENGTH
INDICATOR
MUTE
CONTROL
CLEN
SD/MUTE
SDO
SDO
THRESH
21234-DSH-001-B
Mindspeed Technologies^®
Mindspeed Proprietary and Confidential
April 2010