1 Features
• User-configurable adaptive cable equalizer or
cable driver with integrated reclocker
• Supports ST-2082-1 (12G), ST-2081-1 (6G),
ST-424 (3G), ST-292 (HD), and ST-259 (SD)
• Compatible with DVB-ASI and AES10 (MADI)
• Integrated reclocker locks to SMPTE rates of 11.88
Gbps, 5.94 Gbps, 2.97 Gbps, 1.485 Gbps, or
divide-by-1.001 sub-rates and 270 Mbps
• On-chip 75-Ω termination and return loss
compensation network
• EQ (equalizer) mode:
– Adaptive cable equalizer with integrated
reclocker
– 100-Ω output driver with de-emphasis
– Reclocked 75-Ω loop-through output
– EQ mode cable reach
(Belden 1694A, SDI_OUT disabled):
• 75 m at 11.88 Gbps
• 120 m at 5.94 Gbps
• 200 m at 2.97 Gbps
• 300 m at 1.485 Gbps
• 600 m at 270 Mbps
• Cable driver (CD) mode:
– Dual differential output cable drivers with
integrated reclocker
– Adaptive PCB input equalizer
– Reclocked 100-Ω loopback output
• Automatic pre-emphasis and slew rate control on
75-Ω outputs
• Polarity inversion on 75-Ω and 100-Ω outputs
• Automatic power save in absence of input signal
– Power dissipation: 25 mW (typical)
• Power-down control through ENABLE pin
• Single 2.5-V supply
– EQ mode power dissipation: 275 mW (typical)
– CD mode power dissipation: 305 mW (typical)
• Programmable through pins, SPI, or SMBus
interface
• –40°C to +85°C operating temperature range
• 5-mm × 5-mm, 32-Pin QFN package

2 Applications
• SMPTE compatible serial digital interface
• UHDTV/4K/8K/HDTV/SDTV video
• IP media gateway
• Digital video processing and editing

3 Description
The LMH1297 is a 12G UHD-SDI 75-Ω bidirectional
I/O with integrated reclocker. This device can be
configured either in input mode as an adaptive
cable equalizer or in output mode as a dual cable
driver, allowing system designers the flexibility to
use a single BNC either as an input or output
port, simplifying UHD video hardware designs. The
integrated reclocker locks to all supported SMPTE
data rates up to 11.88 Gbps in both modes. The
bidirectional I/O has an on-chip 75-Ω termination and
return loss compensation network that meets the
stringent SMPTE return loss requirements.
An additional 75-Ω driver output allows the LMH1297
to support a variety of system functions. In EQ
(Equalizer) mode, this second 75-Ω driver can be
used as a loop-through output. In Cable Driver (CD)
mode, this 75-Ω driver can be used as a second
fan-out cable driver. The host-side 100-Ω driver can
also be used as a loop-back output in CD mode for
monitoring purposes.