Texas Instruments INA2181A2IDSQR

Overview

INA2181A2IDSQR from Texas Instruments is a dual-channel, bidirectional current-sense amplifier with 50 V/V fixed gain, –0.2 V to +26 V input common-mode range, ±500 µV max offset at 12 V VCM, and 210 kHz bandwidth. It operates from 2.7 V to 5.5 V supply and delivers rail-to-rail output swing for precision low- and high-side motor current monitoring in industrial power stages.

For engineers reviewing the INA2181A2IDSQR datasheet, INA2181A2IDSQR pinout, INA2181A2IDSQR application, or INA2181A2IDSQR equivalent, key selection criteria include bidirectional sensing capability, 50 V/V gain accuracy (±1% max), 210 kHz small-signal bandwidth, and WSON-10 package compatibility with space-constrained PCB layouts.

Technical Context

The INA2181A2IDSQR integrates matched thin-film gain resistors for 50 V/V fixed gain, minimizing temperature-induced gain drift (≤20 ppm/°C) and enabling accurate current measurement independent of supply voltage. Its proprietary topology supports common-mode voltages up to 26 V - exceeding its 5.5 V max supply - making it suitable for both high-side bus monitoring and low-side ground-referenced sensing.

Each channel features independent REF pins for bidirectional offset control, allowing zero-current output alignment at mid-supply or other user-defined thresholds. The device draws ≤500 µA quiescent current across –40°C to +125°C, with 2 V/µs slew rate ensuring fast response to transient load currents in motor control and battery protection circuits.

Key Specifications

Pinout & Package

INA2181A2IDSQR is housed in a 10-pin WSON package (2.0 mm × 2.0 mm, 0.5 mm pitch) with exposed thermal pad. The package supports reflow-compatible assembly and provides low thermal resistance (R_θJA = 74.5°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bidirectional current-sensing applications.

Compared with INA2181A1IDSQR and INA2181A3IDSQR, the INA2181A2IDSQR offers the optimal balance of sensitivity (50×), bandwidth (210 kHz), and dynamic range for 20–50 mΩ shunts in 24-V industrial systems - avoiding gain saturation while preserving response speed.

Availability

INA2181A2IDSQR is available at Aetrix Electronics and suitable for motor control, battery monitoring, and industrial power management requiring stable component supply across extended temperature and voltage operating conditions.

Supply support for INA2181A2IDSQR 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 precision signal conditioning and power management ICs.

The INAx181 family was designed specifically for cost-optimized, high-accuracy bidirectional current sensing in industrial, automotive, and renewable energy systems - delivering integrated gain, wide common-mode range, and robust thermal performance in compact packages.

FAQ

What is the maximum common-mode voltage supported by the INA2181A2IDSQR?

The INA2181A2IDSQR supports a common-mode input voltage range of –0.2 V to +26 V, independent of its 2.7–5.5 V supply voltage. This allows direct high-side sensing on 24-V industrial buses without external level-shifting circuitry. The specification is validated across the full –40°C to +125°C operating temperature range, and the INA2181A2IDSQR maintains functional integrity even when V_CM exceeds V_S by more than 20 V.

Does the INA2181A2IDSQR require external gain-setting resistors?

No, the INA2181A2IDSQR does not require external gain-setting resistors. It integrates a precision-matched thin-film resistor network configured for fixed 50 V/V gain. This eliminates resistor tolerance errors, thermal tracking mismatches, and PCB layout sensitivity associated with discrete gain networks - directly contributing to the ±1% maximum gain error specification over temperature.

How does the bidirectional sensing capability of the INA2181A2IDSQR work?

The INA2181A2IDSQR achieves bidirectional sensing by referencing each channel's output to its dedicated REF pin. When a positive differential voltage appears across the sense resistor, OUTx rises above V_REFx; a negative differential voltage pulls OUTx below V_REFx. Setting REFx to V_S/2 enables symmetrical ±V_OUT swing around mid-supply, allowing a single-ended ADC to resolve both charge and discharge currents without polarity reversal.

What is the thermal performance of the INA2181A2IDSQR in its WSON-10 package?

The INA2181A2IDSQR in DSQ (WSON-10) package has a junction-to-ambient thermal resistance (R_θJA) of 74.5°C/W and junction-to-board (R_θJB) of 39.8°C/W. With its exposed thermal pad, the device sustains continuous operation at full rated load across –40°C to +125°C ambient when mounted on a 2-layer PCB with ≥1 in² copper pour under the pad. No heatsink is required for typical industrial current-sense power dissipation (<15 mW).

Can the INA2181A2IDSQR be used in low-side current sensing applications?

Yes, the INA2181A2IDSQR is fully specified for low-side current sensing. Its ±150 µV maximum offset at 0 V common-mode voltage enables accurate measurement of small shunt voltages - for example, achieving <±5 mA error with a 20-mΩ resistor at room temperature. The device's rail-to-rail output swing (to within 5 mV of GND) preserves ADC resolution even when sensing near-zero current, and its 2 V/µs slew rate ensures fidelity during fast load transients.