Texas Instruments INA2181A3IDGSR

Overview

INA2181A3IDGSR from Texas Instruments is a dual-channel, bidirectional current-sense amplifier optimized for high-accuracy, low-power current monitoring in both high-side and low-side configurations. It features 100 V/V fixed gain, ±500 µV maximum offset voltage at 12 V common-mode, 150 kHz bandwidth, and operates from 2.7 V to 5.5 V supply across –40°C to +125°C. It is used in motor control feedback loops where precise bidirectional current detection enables real-time torque regulation.

For engineers reviewing the INA2181A3IDGSR datasheet, INA2181A3IDGSR pinout, INA2181A3IDGSR application, or INA2181A3IDGSR equivalent, key selection criteria include its 100 V/V gain accuracy (±1% max), –0.2 V to +26 V input common-mode range independent of supply, rail-to-rail output swing (within 30 mV of VS and 5 mV of GND), and dual-channel channel separation >110 dB at 100 kHz.

Technical Context

The INA2181A3IDGSR implements a precision current-shunt monitor architecture with integrated matched resistor gain network-eliminating external gain-setting components and minimizing temperature-induced gain drift (≤20 ppm/°C). Its differential input stage supports true bidirectional sensing via REF pin biasing, enabling zero-current output centering at VREF.

It uses a proprietary topology that decouples input common-mode voltage (–0.2 V to +26 V) from supply rail constraints (2.7 V–5.5 V), allowing direct connection to 24-V bus rails while powered from a 3.3-V microcontroller domain. The dual-channel layout maintains >110 dB channel-to-channel isolation up to 100 kHz, critical for multi-phase motor current sampling without crosstalk.

Key Specifications

Pinout & Package

INA2181A3IDGSR is housed in a 10-pin VSSOP package (DGS), measuring 3.0 mm × 4.9 mm, with exposed thermal pad recommended for grounding to improve thermal performance (R_θJA = 177.3°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA240A3IDR and MAX40056ATA+T, the INA2181A3IDGSR uniquely balances 26-V VCM tolerance, true bidirectional capability via REF pins, and ultra-low 500-µA quiescent current-making it optimal for dual-channel, battery-powered, or space-constrained 24-V industrial current monitoring where power efficiency and design simplicity are prioritized over extreme bandwidth or ultra-high VCM.

Availability

INA2181A3IDGSR is available at Aetrix Electronics and suitable for motor control feedback, battery pack monitoring, solar inverter DC-link sensing, and industrial power supply overcurrent protection requiring stable component supply across extended temperature and high-reliability production cycles.

Supply support for INA2181A3IDGSR 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 INA2181A3IDGSR belongs to TI's INAx181 family of cost-optimized, bidirectional current-sense amplifiers designed specifically for high-accuracy, low-power current monitoring in motor control, battery management, and power conversion systems operating from 2.7 V to 5.5 V supply.

FAQ

What is the maximum common-mode voltage supported by the INA2181A3IDGSR?

The INA2181A3IDGSR supports a common-mode input voltage range of –0.2 V to +26 V, independent of its 2.7 V to 5.5 V supply voltage. This allows direct high-side sensing on 24-V bus rails without external level-shifting circuitry. The specification is guaranteed across the full –40°C to +125°C operating temperature range, as confirmed in Section 6.3 of the SBOS793H datasheet.

Does the INA2181A3IDGSR require external gain-setting resistors?

No, the INA2181A3IDGSR integrates a precision-matched internal resistor network configured for 100 V/V fixed gain. This eliminates external resistor placement, matching tolerances, and temperature drift concerns-reducing design complexity and improving long-term accuracy. The gain is laser-trimmed at wafer test and specified with ±1% maximum error over temperature.

How does the REF pin enable bidirectional current sensing in the INA2181A3IDGSR?

The REF pin sets the output voltage center point: V_OUT = GAIN × (V_IN+ − V_IN−) + V_REF. Applying V_REF = VS/2 (e.g., 1.65 V on 3.3-V supply) centers zero-current output at mid-scale, allowing positive current to drive output above V_REF and negative current below it. Each channel has its own REF pin, supporting independent calibration in dual-sensing applications.

What is the typical output swing capability of the INA2181A3IDGSR?

The INA2181A3IDGSR provides rail-to-rail output swing: within 30 mV of VS and 5 mV of GND under load (RL = 10 kΩ). This maximizes dynamic range for single-supply ADCs-e.g., delivering 0.005 V to 3.27 V output on a 3.3-V supply. Output swing is characterized across –40°C to +125°C and included in Electrical Characteristics Table 6-5.

Can the INA2181A3IDGSR be used in low-side current sensing with high accuracy?

Yes-the INA2181A3IDGSR achieves ±150 µV maximum offset voltage at VCM = 0 V, enabling high-accuracy low-side sensing. This allows use of smaller shunt resistors (e.g., 5 mΩ instead of 10 mΩ) to reduce power loss while maintaining <1 mA absolute error at zero load. Its 100 dB typical CMRR also suppresses ground noise coupling in noisy industrial environments.