Overview
The LMH1297RTVR, produced by Texas Instruments, is a 12G UHD-SDI 75-Ω bidirectional I/O with an integrated reclocker. This device offers the flexibility to be configured either in input mode as an adaptive cable equalizer or in output mode as a dual cable driver. This versatility allows system designers to use a single BNC port as either an input or output, simplifying UHD video hardware designs. The integrated reclocker supports all SMPTE data rates up to 11.88 Gbps and includes an on-chip 75-Ω termination and return loss compensation network, meeting stringent SMPTE return loss requirements.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Package | QFN (32) | - |
| Package Size | 5.00 mm × 5.00 mm | - |
| Operating Temperature Range | -40 to 85 | °C |
| Supply Voltage (VIN, VDD_CDR) | 2.5 ± 5% | V |
| Power Dissipation (Typical) | 25 mW (EQ mode: 275 mW, CD mode: 305 mW) | mW |
| Cable Reach (Belden 1694A, EQ mode) | 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 | m |
| Thermal Resistance (Junction-to-Ambient) | 32.5 | °C/W |
Key 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) standards
- 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 mode: Adaptive cable equalizer with integrated reclocker, 100-Ω output driver with de-emphasis, reclocked 75-Ω loop-through output
- 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-down control through ENABLE pin
- Programmable through pins, SPI, or SMBus interface
Applications
- SMPTE compatible serial digital interface
- UHDTV/4K/8K/HDTV/SDTV video systems
- IP media gateway
- Digital video processing and editing
Q & A
- What is the primary function of the LMH1297?
The LMH1297 is a 12G UHD-SDI 75-Ω bidirectional I/O with an integrated reclocker, configurable as either an adaptive cable equalizer or a dual cable driver.
- What are the supported SMPTE data rates for the LMH1297?
The LMH1297 supports SMPTE data rates of 11.88 Gbps, 5.94 Gbps, 2.97 Gbps, 1.485 Gbps, or divide-by-1.001 sub-rates and 270 Mbps.
- What is the operating temperature range of the LMH1297?
The operating temperature range is -40°C to 85°C.
- How is the LMH1297 powered?
The LMH1297 is powered from a single 2.5-V supply.
- What is the typical power dissipation of the LMH1297?
The typical power dissipation is 25 mW, with 275 mW in EQ mode and 305 mW in CD mode.
- What are the key features of the EQ mode?
In EQ mode, the LMH1297 features an adaptive cable equalizer with integrated reclocker, a 100-Ω output driver with de-emphasis, and a reclocked 75-Ω loop-through output.
- What are the key features of the CD mode?
In CD mode, the LMH1297 features dual differential output cable drivers with integrated reclocker, an adaptive PCB input equalizer, and a reclocked 100-Ω loopback output.
- How can the LMH1297 be programmed?
The LMH1297 can be programmed through pins, SPI, or SMBus interface.
- What is the purpose of the ENABLE pin?
The ENABLE pin controls the power-down mode of the LMH1297; a logic-low places the device in power-down mode.
- What are some common applications of the LMH1297?
Common applications include SMPTE compatible serial digital interfaces, UHDTV/4K/8K/HDTV/SDTV video systems, IP media gateways, and digital video processing and editing.
