Texas Instruments LMH6646MMX/NOPB

Overview

LMH6646MMX/NOPB from Texas Instruments is a dual, rail-to-rail input and output voltage feedback operational amplifier optimized for low-voltage, low-power, high-speed applications. It delivers 55 MHz −3 dB bandwidth, 22 V/μs slew rate, 650 μA per channel supply current at 2.7 V, ±20 mA linear output current, and 20 mV from rails output swing - enabling precision signal conditioning in battery-powered portable instrumentation and sensor interfaces.

For engineers reviewing the LMH6646MMX/NOPB datasheet, LMH6646MMX/NOPB pinout, LMH6646MMX/NOPB application, or LMH6646MMX/NOPB equivalent, key selection criteria include its dual-channel rail-to-rail I/O performance at micro-power supply current, shutdown capability (via external control on Channel B), crosstalk rejection of 47 dB at 5 MHz, and guaranteed operation from −40°C to +85°C across 2.5 V to 12 V supplies.

Technical Context

The LMH6646MMX/NOPB employs a proprietary VIP10 dielectrically isolated bipolar process with complementary transistors achieving ∼8 GHz f_T under low bias. Its input stage extends common-mode range 0.3 V beyond either supply rail, while the Class A-B "turn-around" input stage reduces offset drift and noise versus conventional architectures.

The output stage uses a common-emitter push-pull configuration delivering ±20 mA into loads while maintaining rail-to-rail swing down to 20 mV from V+ or V− at light loads. Critical parameters - bandwidth, slew rate, and output current - exhibit minimal variation across 2.5 V to 12 V supply range due to process and topology co-optimization.

Key Specifications

Pinout & Package

VSSOP-8 package (3.00 mm × 3.00 mm body size) with exposed thermal pad; RoHS-compliant, lead-free (NOPB suffix).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual rail-to-rail operational amplifier applications.

Compared with TLV2772IDR and OPA2350UA, the LMH6646MMX/NOPB uniquely combines 55 MHz bandwidth, 17 nV/√Hz noise, 47 dB crosstalk rejection, and VSSOP-8 packaging - making it optimal for space-constrained, high-fidelity dual-channel signal paths requiring both speed and channel independence.

Availability

LMH6646MMX/NOPB is available at Aetrix Electronics and suitable for portable medical devices, industrial current sensing, active filtering, and low-voltage video interface applications requiring stable component supply, long-term manufacturability, and RoHS-compliant packaging.

Supply support for LMH6646MMX/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 company designing analog ICs, embedded processors, and digital signal solutions for industrial, automotive, and communications markets.

The LMH6646MMX/NOPB belongs to TI's high-speed, low-power LMH664x amplifier family - engineered specifically for rail-to-rail signal conditioning in battery-operated and space-constrained systems where bandwidth, precision, and efficiency must coexist.

FAQ

What is the maximum supply voltage for the LMH6646MMX/NOPB?

The LMH6646MMX/NOPB supports a supply voltage range of 2.5 V to 12 V (V+ − V−). Absolute maximum rating is 12.6 V. Operation above 12 V risks permanent damage. At 12 V, supply current increases to ~1.6 mA per channel, and output swing remains within 20 mV of rails under light load conditions - confirmed per Electrical Characteristics tables at ±5 V and 10 V test conditions.

Does the LMH6646MMX/NOPB include a shutdown function?

No, the LMH6646MMX/NOPB does not integrate a shutdown pin. Shutdown functionality is exclusive to the LMH6647 (single-channel variant with SD pin). The LMH6646MMX/NOPB is a dual op-amp without enable/disable control; all pins are signal or supply terminals as defined in the VSSOP-8 pinout. Power management must be implemented externally via supply sequencing or series FETs.

What is the input common-mode voltage range of the LMH6646MMX/NOPB?

The LMH6646MMX/NOPB features rail-to-rail input with common-mode range extending 0.3 V beyond both supply rails - e.g., from −0.3 V to V+ + 0.3 V at room temperature. This is validated across −40°C to +85°C and supports direct connection of ground-referenced sensors in single-supply configurations without input biasing networks.

Can the LMH6646MMX/NOPB drive a 50 Ω load?

The LMH6646MMX/NOPB is not optimized for continuous 50 Ω driving. Its specified linear output current is ±20 mA at 0.5 V from rails, supporting ≥250 Ω loads at full swing. For 50 Ω, output swing compresses significantly (e.g., ~1.2 V_PP at 2.7 V supply), and THD rises above −40 dBc. Use only for short-duration pulses or add an external buffer stage for sustained 50 Ω drive.

Is the LMH6646MMX/NOPB pin-compatible with other VSSOP-8 op-amps?

The LMH6646MMX/NOPB follows standard VSSOP-8 pinout for dual op-amps (OUT A, −IN A, +IN A, V−, V+, −IN B, +IN B, OUT B), matching industry conventions. However, electrical behavior - especially rail-to-rail input range, bandwidth, and crosstalk - differs substantially from generic VSSOP-8 op-amps. PCB layout reuse is mechanically possible but requires verification of decoupling, stability, and signal integrity per LMH6646-specific guidelines.