Texas Instruments LMH6672MA

Overview

LMH6672MA from Texas Instruments is a dual, high-speed, high-output-current voltage-feedback operational amplifier designed for demanding line driver applications. It delivers ±200 mA output current into 25 Ω at 9.6 V_PP, achieves 90 MHz −3 dB bandwidth (G = +2), and maintains −105 dBc SFDR at 100 kHz with 8.4 V_PP swing-enabling full-rate upstream ADSL signal integrity on PCI modem cards.

For engineers reviewing the LMH6672MA datasheet, LMH6672MA pinout, LMH6672MA application, or LMH6672MA equivalent, key selection criteria include output drive capability into 25–100 Ω loads, distortion performance at xDSL frequencies, single- or dual-supply operation (5 V to 12 V), thermal management in SOIC packaging, and stability at minimum gain of +2 V/V.

Technical Context

The LMH6672MA employs a Class AB output stage optimized for low-distortion, high-current delivery into low-impedance loads (25–100 Ω), with internal idle current (~4.8 mA per channel) routed into the load during signal swing to reduce quiescent dissipation. Its voltage-feedback architecture ensures predictable compensation and stable operation at gains ≥ +2 V/V without external compensation.

It operates across ±2.5 V to ±6.5 V supplies (5–13 V total), supports rail-to-rail output swing within 1 V of rails, and features input common-mode range extending to −6 V (at ±6 V supply). Thermal design is critical: SOIC package has R_θJA = 172 °C/W, requiring attention to ambient temperature and power delivery in DSL line driver configurations.

Key Specifications

Pinout & Package

LMH6672MA is housed in an 8-pin SOIC (D) package, 4.89 mm × 3.90 mm body size, with exposed pad floating (not internally connected). Pinout is identical for both channels in dual configuration.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-output-current op amp applications.

Compared with LMH6672MA, LMH6672MR/NOPB offers superior thermal performance in the same functional footprint, while THS3202D provides higher speed and current but demands additional design effort for stability and layout-making LMH6672MA optimal for cost-sensitive, thermally moderate xDSL line driver upgrades.

Availability

LMH6672MA is available at Aetrix Electronics and suitable for ADSL PCI modem cards, xDSL external modems, and line driver circuits requiring stable component supply with full production lifecycle support through 2030.

Supply support for LMH6672MA 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 and embedded processing technologies, with decades of expertise in high-speed op amps and communications infrastructure ICs.

The LMH6672MA belongs to TI's high-output-current, low-distortion op amp product line, engineered specifically for xDSL line driver applications where high slew rate, wide bandwidth, and robust thermal behavior are essential under real-world loading conditions.

FAQ

What is the maximum output voltage swing of the LMH6672MA into a 25 Ω load?

The LMH6672MA delivers ±4.8 V output swing into a 25 Ω load at ±6 V supply, corresponding to 9.6 V_PP. This is confirmed in Section 6.5 Electrical Characteristics under "VO Output Swing" with RL = 25 Ω and VS = ±6 V. The device maintains this swing across −40°C to +125°C operating temperature, making it suitable for industrial-grade xDSL line drivers where thermal stability is critical. LMH6672MA achieves this with only 1 V headroom from each rail.

Is the LMH6672MA stable at unity gain (G = +1)?

No, the LMH6672MA is not unity-gain stable. It is specified and guaranteed stable only for gains of +2 V/V or higher, as explicitly stated in the Features section and Recommended Operating Conditions. Attempting G = +1 will cause peaking or oscillation due to insufficient phase margin. For unity-gain applications, TI recommends alternatives such as the OPA695 or THS3091, which are explicitly unity-gain compensated. LMH6672MA must be used with minimum closed-loop gain of +2.

Can the LMH6672MA drive a 50 Ω differential load directly?

Yes-the LMH6672MA is routinely configured as a differential output driver to drive 50 Ω loads, achieving 16.8 V_PP swing with −98 dBc distortion at full-rate ADSL upstream frequencies. This is validated in the datasheet's Description section and Typical Application diagram, where two LMH6672 channels are used in anti-phase configuration with a center-tapped transformer. No external current-boosting components are needed, as each channel delivers ±200 mA into 25 Ω, satisfying the 50 Ω differential requirement.

What is the thermal resistance (R_θJA) of the LMH6672MA package?

The LMH6672MA uses an 8-pin SOIC (D) package with a junction-to-ambient thermal resistance (R_θJA) of 172 °C/W, as specified in Section 6.4 Thermal Information. This value assumes standard JEDEC 2-layer board mounting. At maximum recommended ambient temperature (85°C) and worst-case power dissipation (216 mW), junction temperature reaches ~122°C-well below the 150°C absolute maximum. For higher-power or elevated-ambient use, the LMH6672MR/NOPB (SO PowerPAD) variant reduces R_θJA to 58.6 °C/W.

Does the LMH6672MA support single-supply operation?

Yes, the LMH6672MA supports true single-supply operation from 5 V to 12 V, with input common-mode range extending down to ground (0 V) and output swing within 1 V of ground. Section 6.3 Recommended Operating Conditions specifies supply voltage range as ±2.5 V to ±6.5 V (i.e., 5–13 V total), and Figure 1–5 in Typical Performance Characteristics show valid operation at +5 V and +12 V supplies. LMH6672MA is widely deployed in 5 V PCI modem cards and 12 V external xDSL modems without dual-rail generation.