PRELIMINARY
April 2007
LMH0346
3Gbps HD/SD SDI Reclocker with Dual Differential Outputs
General Description
Features
The LMH0346 3Gbps HD/SD SDI Reclocker retimes serial
digital video data conforming to the SMPTE 424M, SMPTE
292M, and SMPTE 259M (C) standards. The LMH0346 op-
erates at serial data rates of 270 Mbps, 1.483 Gbps, 1.485
Gbps, 2.967 Gbps, and 2.97 Gbps. The LMH0346 supports
DVB-ASI operation at 270 Mbps.
Supports SMPTE 424M, SMPTE 292M, and SMPTE
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259M (C) serial digital video standards
Supports 270 Mbps, 1.483 Gbps, 1.485 Gbps, 2.967
Gbps, and 2.97 Gbps serial data rate operation
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Supports DVB-ASI at 270 Mbps
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Single 3.3V supply operation
The LMH0346 automatically detects the incoming data rate
and adjusts itself to retime the incoming data to suppress ac-
cumulated jitter. The LMH0346 recovers the serial data-rate
clock and optionally provides it as an output. The LMH0346
has two differential serial data outputs; the second output may
be selected as a low-jitter, data-rate clock output (DDR clock
at 3Gbps). Controls and indicators are: serial clock or second
serial data output select, manual rate select input, SD/HD rate
indicator output, lock detect output, auto/manual data bypass
and output mute. The serial data inputs, outputs, and serial
clock outputs are differential LVPECL compatible. The CML
serial data and serial clock outputs are suitable for driving
100Ω differentially terminated networks. The control logic in-
puts and outputs are LVCMOS compatible.
370 mW typical power consumption
Two differential, reclocked outputs
Choice of second reclocked output or low-jitter,
differential, data-rate clock output (DDR clock at 3Gbps)
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Single 27 MHz external crystal or reference clock input
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Manual rate select input
SD/HD operating rate indicator output
Lock Detect indicator output
Output mute function for data and clock
Auto/Manual reclocker bypass
Differential LVPECL compatible serial data inputs and
outputs
The LMH0346 is powered from a single 3.3V supply. Power
dissipation is typically 370 mW. The device is housed in a 20-
pin e-TSSOP package.
LVCMOS control inputs and indicator outputs
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20-Pin e-TSSOP package
Industrial temperature range: -40°C to +85°C
Footprint compatible with the LMH0046
Applications
SDTV/HDTV and 3Gbps serial digital video interfaces for:
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Digital video routers and switchers
Digital video processing and editing equipment
DVB-ASI equipment
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Video standards and format converters
Typical Application
20215001
© 2007 National Semiconductor Corporation
202150
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