Texas Instruments INA271AID

Overview

INA271AID from Texas Instruments is a unidirectional, voltage-output current-shunt monitor with 20 V/V fixed gain, –16 V to +80 V input common-mode range, 130 kHz bandwidth, and ±0.2% typical gain error. It senses shunt voltage drops in high-side or low-side configurations for precision power management in automotive and telecom systems.

For engineers reviewing the INA271AID datasheet, INA271AID pinout, INA271AID application, or INA271AID equivalent, key selection criteria include its wide common-mode tolerance, integrated preamp/buffer architecture enabling external filtering, SOIC-8 package compatibility, and operation across –40°C to +125°C industrial temperature range.

Technical Context

The INA271AID implements a two-stage amplifier architecture: a high-common-mode preamplifier stage followed by a unity-gain buffer (BUF IN → OUT), with PRE OUT providing access to the preamp output at 96 kΩ impedance. This enables configurable single-pole or Sallen-Key filtering without external op amps.

Its differential input stage operates independently of supply voltage, supporting accurate sensing even when VCM exceeds V+ (up to +80 V) or falls below GND (down to –16 V). Gain accuracy is specified over full temperature range with 50 ppm/°C max gain drift and 2.5 μV/°C typical offset drift.

Key Specifications

Pinout & Package

INA271AID is housed in an SOIC-8 package (4.90 mm × 3.91 mm body size) with standard JEDEC MS-012AC footprint and gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar current-sense amplifier applications.

Compared with INA271AID, INA240A1D adds bidirectional capability at the cost of increased design complexity, while MAX4080TASA+ trades bandwidth and quiescent current for broader vendor availability-making INA271AID optimal for high-speed, low-power unidirectional sensing in space-constrained SOIC layouts.

Availability

INA271AID is available at Aetrix Electronics and suitable for automotive battery monitoring, telecom DC distribution, laptop adapter power management, and industrial welding equipment requiring stable component supply across extended temperature and voltage ranges.

Supply support for INA271AID 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 analog ICs and industrial-grade signal conditioning solutions.

The INA27x product line was designed specifically for high-accuracy, high-common-mode current sensing in automotive, telecom, and industrial power systems-emphasizing robustness, ease of filtering, and wide operating range without external components.

FAQ

What is the maximum common-mode voltage the INA271AID can withstand?

The INA271AID supports a common-mode input voltage range from –16 V to +80 V, independent of supply voltage. This allows direct high-side sensing in 48 V telecom systems and survival of automotive load-dump transients up to +80 V without external protection circuitry. The specification is guaranteed over the full –40°C to +125°C temperature range.

Does the INA271AID require external filtering components?

The INA271AID does not require external filtering but provides dedicated PRE OUT and BUF IN pins to enable optional RC or Sallen-Key filtering. Its 96 kΩ PRE OUT impedance simplifies single-pole filter design (e.g., 1 nF capacitor yields ~1.7 kHz cutoff). Filtering is recommended for anti-aliasing in ADC-based systems or noise suppression in electrically noisy environments like welding equipment.

Can the INA271AID measure bidirectional current flow?

No, the INA271AID is a unidirectional current-shunt monitor optimized for sensing current in one direction only-typically from supply to load. It lacks the internal architecture to resolve negative VSENSE polarity. For bidirectional applications such as motor control with regeneration, TI recommends the INA240 series, which provides true symmetric ±VSENSE measurement capability.

What is the output swing capability of the INA271AID at 125°C?

At +125°C, the INA271AID output swings to within 200 mV of V+ and 50 mV above GND when driving a 10 kΩ load. For example, with V+ = 12 V, the guaranteed output range is 0.05 V to 11.8 V. This rail-to-rail limitation must be considered when interfacing with ADC reference voltages or comparator thresholds in high-temperature industrial deployments.

How does the INA271AID handle low-sense-voltage conditions below 20 mV?

Below 20 mV VSENSE, the INA271AID exhibits degraded accuracy due to internal amplifier topology transitions. At VSENSE = 0 mV and VCM between 0 V and V+, output may peak up to 0.4 V (INA271-specific limit); accuracy recovers fully above 20 mV. Applications requiring sub-20 mV resolution should use zero-drift amplifiers or oversampling techniques-not the INA271AID.