Texas Instruments LMH0026MH/NOPB

Overview

LMH0026MH/NOPB from Texas Instruments is an SD SDI reclocker IC that retimes 270 Mbps serial digital video data per SMPTE 259M-C, suppresses accumulated jitter using a PLL-based architecture, provides two differential LVPECL-compatible outputs, and supports DVB-ASI at identical data rate - deployed in digital video routers, switchers, and format converters.

For engineers reviewing the LMH0026MH/NOPB datasheet, LMH0026MH/NOPB pinout, LMH0026MH/NOPB application, or LMH0026MH/NOPB equivalent, key selection criteria include 270 Mbps jitter tolerance (≥0.6 UIP-P), dual-output configuration flexibility (data vs. clock on SCO/SDO2), 20-pin HTSSOP thermal performance (θJA = 26.6°C/W), and industrial temperature operation (−40°C to +85°C).

Technical Context

The LMH0026MH/NOPB implements a PLL-based reclocking architecture with 300 kHz loop bandwidth and <0.1 dB peaking, recovering a clean 270 MHz clock from incoming 270 Mbps SDI data. It uses a 27 MHz crystal or external reference for frequency synthesis and features auto-bypass functionality when unlocked or presented with unsupported rates.

Its dual differential outputs (SDO and SCO/SDO2) are CML/LVPECL compatible, delivering 800 mVP-P ±10% into 100 Ω differentially terminated loads. Control logic (LVCMOS) enables dynamic selection of SCO/SDO2 as either second retimed data or low-jitter 270 MHz clock output, with lock detect (active-high), SD indicator, and output mute functions.

Key Specifications

Pinout & Package

LMH0026MH/NOPB is housed in a 20-pin HTSSOP (PWP) package with exposed die attach pad (DAP) electrically connected to VEE (ground); DAP must be soldered to PCB ground plane for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SDI reclocking applications.

Compared with LMH0046MH/NOPB and LMH0346RTVT, LMH0026MH/NOPB delivers lowest power (330 mW), smallest footprint (20-pin HTSSOP), and dedicated SD-optimized jitter performance (0.02 UIP-P), making it the most efficient choice for cost-driven, thermally constrained SD-SDI infrastructure where HD capability is unnecessary.

Availability

LMH0026MH/NOPB is available at Aetrix Electronics and suitable for digital video routers, DVB-ASI equipment, and video format converters requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for LMH0026MH/NOPB 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 leader specializing in analog, embedded processing, and connectivity technologies, with broad portfolio coverage across industrial, automotive, and communications markets.

The LMH0026MH/NOPB belongs to TI's high-speed video interface product line, engineered specifically for SMPTE-compliant serial digital video signal conditioning in broadcast, professional AV, and digital signage systems.

FAQ

What is the primary function of the LMH0026MH/NOPB in an SDI signal chain?

The LMH0026MH/NOPB functions as a jitter-suppressing reclocker for 270 Mbps SD-SDI signals conforming to SMPTE 259M-C. It recovers a clean 270 MHz clock from the incoming serial data stream and provides two differential outputs - one fixed retimed data output (SDO) and one configurable output (SCO/SDO2) that can deliver either a second data stream or the recovered clock. This ensures signal integrity across long cable runs and multi-stage video processing systems. The LMH0026MH/NOPB achieves this using a PLL with 300 kHz loop bandwidth and delivers ultra-low output jitter (0.02–0.08 UIP-P for data, 2–3 psRMS for clock).

Can the LMH0026MH/NOPB operate with an external 27 MHz clock instead of a crystal?

Yes, the LMH0026MH/NOPB supports both a 27 MHz parallel-resonant crystal connected between XTAL IN/EXT CLK and XTAL OUT pins, and a 27 MHz LVCMOS-compatible external clock applied solely to the XTAL IN/EXT CLK pin. The device requires ±50 ppm frequency tolerance on the reference source, and the internal oscillator circuitry is designed to lock reliably to either source. When using an external clock, the XTAL OUT pin is left unconnected. This flexibility allows designers to choose between low-cost crystal networks or precision clock generators depending on system jitter and synchronization requirements. The LMH0026MH/NOPB maintains full specification compliance in both configurations.

How does the SCO_EN pin affect the functionality of the LMH0026MH/NOPB?

SCO_EN is an LVCMOS input with internal pulldown that controls the function of the SCO/SDO2 differential output pair. When SCO_EN is low (default state), SCO/SDO2 delivers a second retimed serial data output. When SCO_EN is driven high, SCO/SDO2 instead delivers the recovered 270 MHz serial data-rate clock. This selection is independent of other control pins and remains active even during auto-bypass mode - though the clock output is muted if OUTPUT MUTE is asserted or if bypass is forced via BYPASS/AUTO BYPASS. The LMH0026MH/NOPB's ability to dynamically configure this output eliminates the need for external clock buffers in many SDI distribution architectures.

What thermal considerations apply to the LMH0026MH/NOPB in continuous operation?

The LMH0026MH/NOPB dissipates 330 mW typical power and uses a 20-pin HTSSOP package with an exposed die attach pad (DAP) connected to VEE (ground). To maintain junction temperature within safe limits (≤150°C), the DAP must be soldered to a minimum 200 mm² copper pour on the PCB's ground plane. With proper thermal land design, the package achieves θJA = 26.6°C/W, resulting in ~8.7°C rise above ambient at full load. Operation at maximum ambient (85°C) yields junction temperature of ~93.7°C - well within specification. No heatsink or airflow is required for standard deployments. The LMH0026MH/NOPB's thermal design enables reliable use in densely packed video processing modules without derating.

Is the LMH0026MH/NOPB compatible with DVB-ASI signals?

Yes, the LMH0026MH/NOPB explicitly supports DVB-ASI operation at 270 Mbps, sharing identical electrical and timing specifications with SMPTE 259M-C SD-SDI. It retimes incoming DVB-ASI streams with the same jitter tolerance (≥0.6 UIP-P input), output jitter performance (0.02–0.08 UIP-P), and LVPECL-compatible differential signaling. The device does not perform protocol decoding or packet inspection - it operates purely at the physical layer, making it suitable for ASI transport stream regeneration in satellite receivers, conditional access gateways, and broadcast contribution links. All control features (lock detect, output mute, auto-bypass) function identically for DVB-ASI as they do for SD-SDI. The LMH0026MH/NOPB is therefore a dual-standard solution for broadcast infrastructure requiring interoperability across both domains.