Texas Instruments LMH6647MF

Overview

LMH6647MF from Texas Instruments is a single-channel, rail-to-rail input and output voltage feedback operational amplifier with shutdown control, designed for low-voltage, high-speed signal conditioning. It delivers 55 MHz −3 dB bandwidth, 22 V/μs slew rate, and ±20 mA linear output current at 2.7 V supply, enabling use in portable instrumentation and multiplexed sensor interfaces where power gating and wide dynamic range are critical.

For engineers reviewing the LMH6647MF datasheet, LMH6647MF pinout, LMH6647MF application, or LMH6647MF equivalent, key selection criteria include its 650 μA quiescent current (active), <50 μA shutdown current, rail-to-rail I/O swing within 20 mV of rails, 17 nV/√Hz input voltage noise, and SOT-23-6 package compatibility with space-constrained PCB layouts.

Technical Context

The LMH6647MF employs a proprietary VIP10 dielectrically isolated bipolar process to sustain high ft (~8 GHz) under low 2.7 V supply and low bias current. Its rail-to-rail 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 power dissipation versus comparable speed amplifiers.

The output stage uses a common-emitter push-pull topology capable of sourcing/sinking ±20 mA while maintaining output swing within 20 mV of V+ or V− at light loads. Performance parameters-including bandwidth, slew rate, and output current-exhibit minimal variation across 2.5 V to 12 V supply range, supporting flexible system-level voltage scaling.

Key Specifications

Pinout & Package

SOT-23-6 package (2.92 mm × 1.60 mm body size) with exposed pad for thermal enhancement; compatible with standard pick-and-place and reflow processes.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed, low-power op-amp applications.

Compared with LMH6647MF, LMH6645MF removes shutdown control to reduce cost and footprint, while OPA355DBVR trades 4× higher supply current for improved noise and speed-making LMH6647MF optimal for battery-operated, multiplexed, or space-constrained high-speed analog signal paths.

Availability

LMH6647MF is available at Aetrix Electronics and suitable for portable instrumentation, multiplexed sensor interfaces, current sense amplification, and high-speed active filtering requiring stable component supply across industrial temperature range (−40°C to +85°C) and long-term production continuity.

Supply support for LMH6647MF 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 precision amplifiers, data converters, and power management ICs.

The LMH664x product line was engineered for low-voltage, high-speed signal conditioning in portable and power-sensitive applications-delivering rail-to-rail I/O, micro-power shutdown, and consistent performance from 2.5 V to 12 V supply.

FAQ

What is the shutdown threshold voltage for LMH6647MF at 2.7 V supply?

The LMH6647MF shutdown threshold voltage is specified as 1.95 V (minimum) to 2.30 V (maximum) when operating at V+ = 2.7 V. Below this range, the device enters shutdown mode drawing <50 μA total supply current. This threshold is internally referenced and remains stable across temperature (−40°C to +85°C), ensuring reliable power gating in battery-voltage–driven systems. The LMH6647MF datasheet confirms this behavior in Section 7.5 Electrical Characteristics.

Can LMH6647MF drive a 50 Ω load while maintaining rail-to-rail output swing?

The LMH6647MF is not characterized to maintain rail-to-rail swing into 50 Ω. Its ±20 mA linear output current specification applies at VOUT = 0.5 V from rails into ≥1 kΩ loads. Driving 50 Ω would require ±50 mA minimum for full swing, exceeding LMH6647MF's safe operating capability and risking thermal overload or distortion. For 50 Ω applications, TI recommends buffer stages or dedicated line drivers like THS3201. LMH6647MF is optimized for high-impedance loads typical in ADC drivers and active filters.

Does LMH6647MF support dual-supply operation, and what is its maximum allowable supply voltage?

Yes, LMH6647MF supports dual-supply operation (e.g., ±2.5 V, ±5 V) as confirmed by electrical characteristics tables across ±5 V conditions. Its absolute maximum supply voltage (V+ − V−) is 12.6 V, with recommended operating range from 2.5 V to 12 V total span. At ±5 V, it delivers 55 MHz bandwidth, 22 V/μs slew rate, and output swing to within 50 mV of rails-enabling use in legacy industrial signal chains requiring symmetric supplies. LMH6647MF maintains parameter stability across all valid supply configurations.

How does LMH6647MF's input common-mode voltage range compare to standard rail-to-rail op-amps?

LMH6647MF extends its input common-mode voltage range 0.3 V beyond both supply rails (e.g., −0.3 V to 3.0 V at 2.7 V single supply), exceeding typical rail-to-rail op-amps that only reach the rails. This allows direct connection to signals slightly outside the supply domain-such as shunt-based current sense nodes or AC-coupled sources with DC offsets-without external clamping or level-shifting. The LMH6647MF achieves this via proprietary VIP10 bipolar input stage, validated across −40°C to +85°C in datasheet Figure 26–28.

Is LMH6647MF unity-gain stable, and what is its phase margin at AV = +1?

Yes, LMH6647MF is unity-gain stable, with phase margin ≥60° at AV = +1 as verified by closed-loop frequency response plots (Figure 1 and Figure 2 in SNOS970D). Its internal compensation ensures stability with capacitive loads up to 100 pF and resistive feedback networks. No external compensation is required for standard unity-gain buffer or inverter configurations. This stability holds across supply voltages (2.7 V to ±5 V) and temperature (−40°C to +85°C), making LMH6647MF suitable for precision unity-gain applications without risk of oscillation.