Texas Instruments LMH0046MH

Overview

LMH0046MH from Texas Instruments is a HD/SD SDI reclocker IC designed for serial digital video signal retiming in broadcast and professional video systems. It supports SMPTE 259M (143/270 Mbps) and SMPTE 292M (1.483/1.485 Gbps), delivers two differential LVPECL-compatible outputs, consumes 330 mW typical power, and operates from a single 3.3 V supply across −40°C to +85°C.

For engineers reviewing the LMH0046MH datasheet, LMH0046MH pinout, LMH0046MH application, or LMH0046MH equivalent, this page provides verified technical context, jitter-suppression performance metrics, dual-output configuration options, crystal-referenced PLL architecture, and real-world integration guidance for SDI routing, conversion, and DVB-ASI equipment.

Technical Context

The LMH0046MH implements a CML-input, LVPECL-compatible PLL-based retimer with auto-rate detection and manual rate select (RATE0/RATE1). Its loop bandwidth is 300 kHz at 270 Mbps and 2.0 MHz at 1485 Mbps, enabling stable lock under varying input jitter conditions per SMPTE RP 184-1996.

It features dual differential outputs: SDO (fixed retimed data) and SCO/SDO2 (multiplexed between second retimed data or low-jitter serial clock), controlled by SCO_EN. The device uses a 27 MHz ±50 ppm crystal reference and includes lock detect (LOCK DET), SD/HD rate indicator, and output mute (OP MUTE) for system-level synchronization and fault management.

Key Specifications

Pinout & Package

LMH0046MH is housed in a 20-pin HTSSOP (PWP) package with exposed die attach pad (DAP) electrically connected to VEE (ground). The package supports surface-mount reflow per JEDEC Level-3 (260°C peak).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LMH0046MTX/NOPB, the LMH0046MH offers superior thermal performance and proven reliability in high-density video chassis; compared with LMH0344RTVT, it provides dual-output versatility and DVB-ASI compatibility at lower bandwidth - making LMH0046MH optimal for SMPTE 259M/292M routing and conversion systems.

Availability

LMH0046MH is available at Aetrix Electronics and suitable for digital video routers, broadcast-grade format converters, DVB-ASI transmitters, and professional editing systems requiring stable component supply across extended production lifecycles.

Supply support for LMH0046MH 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 solutions for industrial, automotive, and communications markets.

The LMH0046MH belongs to TI's broadcast video interface product line, engineered specifically for SMPTE-compliant signal integrity restoration in professional video infrastructure - emphasizing jitter suppression, multi-standard rate agility, and system-level control integration.

FAQ

What video standards does the LMH0046MH support?

The LMH0046MH supports SMPTE 259M (143 Mbps and 270 Mbps) for standard-definition digital video and SMPTE 292M (1.483 Gbps and 1.485 Gbps) for high-definition digital video. It also handles DVB-ASI transport streams at 270 Mbps. All supported rates are explicitly validated in the SNLS222F datasheet, and the device rejects harmonics like 360 Mbps to prevent false locking. The LMH0046MH does not support SMPTE 424M (3G-SDI) or higher rates.

How does the LMH0046MH handle input jitter, and what is its output jitter performance?

The LMH0046MH tolerates >6 UI_P-P input jitter at 143/270 Mbps and >0.6 UI_P-P at 1483/1485 Mbps, meeting SMPTE RP 184-1996 requirements. Its retimed SDO output achieves 0.05 UI_P-P typical jitter at 1485 Mbps, while the SCO/SDO2 serial clock output delivers 2–3 ps_RMS phase noise. These values are measured with 0.2 UI_P-P input jitter and confirmed across voltage and temperature ranges per the AC Electrical Characteristics table in the LMH0046MH datasheet.

Can the LMH0046MH operate without an external crystal?

No - the LMH0046MH requires a 27 MHz ±50 ppm parallel-resonant crystal connected between XTAL IN/EXT CLK and XTAL OUT pins, or a 27 MHz LVCMOS-compatible clock source applied to XTAL IN/EXT CLK. The device lacks an internal oscillator and will not function without this reference. Table 4 in the LMH0046MH datasheet specifies crystal parameters including 20 pF load capacitance, ≤40 Ω series resistance, and 100 µW recommended drive level.

What is the function of the SCO_EN pin on the LMH0046MH?

The SCO_EN pin on the LMH0046MH controls the multiplexed SCO/SDO2 output: when high, it enables a low-jitter serial data-rate clock; when low (its internal pull-down default), it enables a second retimed serial data output. This pin directly selects the functional mode of pins 13 and 14, and its state determines whether the LMH0046MH serves as a dual-data reclocker or a data-plus-clock generator - critical for system-level clock distribution architecture.

Does the LMH0046MH support automatic bypass when the PLL loses lock?

Yes - when the BYPASS/AUTO-BP pin is held low, the LMH0046MH automatically enters bypass mode if the PLL loses lock or detects an unsupported data rate (e.g., 360 Mbps). In this state, the input signal passes through unretimed to SDO, while SCO/SDO2 is muted. This behavior is documented in Table 3 of the LMH0046MH datasheet and ensures signal continuity during transient loss-of-lock events without requiring external intervention.