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.