Texas Instruments LMH1297RTVR

Overview

LMH1297RTVR from Texas Instruments is a 12G UHD-SDI bidirectional I/O with integrated reclocker, functioning as either an adaptive cable equalizer (EQ mode) or dual cable driver (CD mode) on a single 75-Ω BNC port. It supports SMPTE ST-2082-1 (11.88 Gbps), ST-2081-1 (5.94 Gbps), and legacy SD/HD rates, delivers <0.18 UIp-p reclocked output jitter at 11.88 Gbps over 75 m of Belden 1694A, and operates from a single 2.5-V supply in a 5-mm × 5-mm 32-pin QFN package for broadcast video routing hardware.

For engineers reviewing the LMH1297RTVR datasheet, LMH1297RTVR pinout, LMH1297RTVR application, or LMH1297RTVR equivalent, this page delivers verified functional modes (EQ/CD), SMPTE-compliant return loss performance, reclocker lock behavior, power dissipation across operating modes (25–485 mW), and precise pin-level interface definitions - all critical for UHD-SDI board bring-up, signal integrity validation, and failover-capable video infrastructure design.

Technical Context

The LMH1297RTVR implements a fully integrated CDR with built-in loop filter and no external reference clock required; it locks to SMPTE rates from 270 Mbps to 11.88 Gbps and provides eye opening monitoring plus programmable LOCK_N output for system diagnostics. Its bidirectional architecture uses shared SDI_IO± pins with on-chip 75-Ω termination and return loss compensation networks meeting SMPTE RP 184 requirements.

In EQ mode, the device processes incoming SDI signals through an adaptive line-side equalizer and outputs reclocked data via SDI_IO± (loop-through) and SDI_OUT± (fan-out), while in CD mode it accepts host-side 100-Ω differential inputs (IN0±), applies adaptive PCB equalization, and drives two independent 75-Ω coaxial outputs (SDI_IO± and SDI_OUT±) with programmable pre-emphasis and slew rate control.

Key Specifications

Pinout & Package

LMH1297RTVR is housed in a 5.00 mm × 5.00 mm, 32-pin QFN package (RTV) with exposed thermal pad (EP = VSS). The package supports standard reflow profiles and requires 3×3 via array under EP for optimal thermal performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar UHD-SDI bidirectional I/O applications.

Compared with LMH1227RTVR and GS2972A-IBE3, the LMH1297RTVR uniquely combines bidirectional 75-Ω I/O, adaptive cable equalization, dual 75-Ω outputs, and host-side 100-Ω interfaces in one package - enabling flexible, space-constrained UHD-SDI hardware that adapts to changing signal integrity conditions without redesign.

Availability

LMH1297RTVR is available at Aetrix Electronics and suitable for broadcast video routers, UHDTV camera backhaul systems, and IP media gateways requiring stable component supply, long-term lifecycle support, and SMPTE-compliant signal integrity performance.

Supply support for LMH1297RTVR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor company specializing in analog and embedded processing technologies, with leadership in high-speed interface, signal chain, and power management ICs for industrial, automotive, and communications markets.

The LMH1297RTVR belongs to TI's high-speed serial digital interface product line, designed specifically for SMPTE-compliant UHD video infrastructure - addressing the need for integrated, low-jitter, bidirectional reclocking in broadcast-grade equipment.

FAQ

What is the primary function of the LMH1297RTVR in a UHD-SDI system?

The LMH1297RTVR serves as a configurable 12G UHD-SDI bidirectional I/O with integrated reclocker. It operates either as an adaptive cable equalizer to restore degraded signals or as a dual cable driver to transmit reclocked video, enabling flexible use of a single BNC port in broadcast routing, camera backhaul, and IP gateway hardware. Its core value lies in eliminating separate equalizer/driver ICs while maintaining SMPTE compliance across all supported data rates.

Does the LMH1297RTVR require an external reference clock for its reclocker?

No, the LMH1297RTVR does not require an external reference clock. Its integrated reclocker uses a built-in loop filter and locks directly to incoming SMPTE data rates - including 11.88 Gbps, 5.94 Gbps, 2.97 Gbps, 1.485 Gbps, and 270 Mbps - using only the embedded clock recovery circuitry. This self-contained operation simplifies system clock architecture and reduces component count in UHD-SDI designs.

How does the LMH1297RTVR handle cable length variation in EQ mode?

In EQ mode, the LMH1297RTVR employs adaptive cable equalization that automatically compensates for signal loss across varying coaxial cable lengths: up to 75 m at 11.88 Gbps, 120 m at 5.94 Gbps, and 600 m at 270 Mbps (Belden 1694A). This eliminates manual gain adjustment and ensures consistent signal integrity without firmware intervention or external calibration - critical for field-deployable broadcast equipment.

What are the power supply requirements for the LMH1297RTVR?

The LMH1297RTVR operates from a single 2.5-V ±5% supply applied to VIN and VDD_CDR. It draws 110–200 mA in EQ mode and 122–230 mA in CD mode (typical), with power dissipation ranging from 275 mW (EQ) to 485 mW (CD) depending on enabled outputs and data rate. An internal 1.8-V LDO (VDD_LDO) powers core logic and requires external 1-µF and 0.1-µF bypass capacitors to VSS.

Can the LMH1297RTVR be configured via hardware pins or only through serial interface?

The LMH1297RTVR supports both hardware pin-strapping and serial programming. Mode selection (EQ/CD), output enable (SDI_OUT_SEL, OUT0_SEL), and voltage control (SDI_VOD, HOST_EQ0) can be set using LVCMOS or 4-level logic pins at power-up. Additionally, full register access is available via SPI or SMBus interfaces when MODE_SEL is configured - providing flexibility for factory programming or runtime reconfiguration.