Texas Instruments INA2181A3IDGST

Overview

INA2181A3IDGST from Texas Instruments is a dual-channel, bidirectional current-sense amplifier with 100 V/V fixed gain, –0.2 V to +26 V input common-mode range, ±500 µV max offset at 12 V VCM, and 150 kHz small-signal bandwidth. It enables precision high- and low-side current monitoring in motor control and battery management systems where bus voltage exceeds supply rail.

For engineers reviewing the INA2181A3IDGST datasheet, INA2181A3IDGST pinout, INA2181A3IDGST application, or INA2181A3IDGST equivalent, key selection criteria include its 100× gain accuracy (±1% max), 2 V/µs slew rate, 500 µA max quiescent current, rail-to-rail output swing (within 30 mV of VS and 5 mV of GND), and operation across –40°C to +125°C.

Technical Context

The INA2181A3IDGST integrates matched thin-film resistor networks for stable 100 V/V gain with ≤20 ppm/°C drift and supports bidirectional sensing via REF pin biasing. Its proprietary topology decouples common-mode input range (–0.2 V to +26 V) from supply voltage (2.7 V to 5.5 V), enabling direct high-side connection to 24-V bus rails without level-shifting.

Each channel features independent IN+, IN–, OUT, and REF terminals, allowing differential current measurement across two separate shunt resistors. Channel separation exceeds 100 dB at 10 kHz, minimizing crosstalk in dual-sensor applications such as phase-current monitoring in 3-phase inverters.

Key Specifications

Pinout & Package

INA2181A3IDGST is housed in a 10-pin VSSOP package (DGS), 3.0 mm × 4.9 mm, with exposed thermal pad (optional GND connection). Pin functions are validated per TI SBOS793H Rev H.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA226AIRSAT and MAX40056AUB+, the INA2181A3IDGST uniquely delivers dual-channel analog output, 26-V common-mode capability, and 100× gain in one VSSOP package-reducing component count and layout complexity for multi-rail current monitoring without sacrificing speed or temperature stability.

Availability

INA2181A3IDGST is available at Aetrix Electronics and suitable for motor control, battery monitoring, and solar inverter designs requiring stable component supply, extended temperature operation, and high-accuracy bidirectional current sensing.

Supply support for INA2181A3IDGST 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-reliability current sensing in industrial, automotive, and renewable energy systems-emphasizing wide common-mode range, low drift, and seamless integration with standard microcontrollers.

FAQ

What is the maximum common-mode voltage the INA2181A3IDGST can handle?

The INA2181A3IDGST supports a common-mode input voltage range from –0.2 V to +26 V, independent of its 2.7–5.5 V supply voltage. This allows direct connection to 24-V bus rails in high-side configurations without external level-shifting circuitry. The specification is validated across the full –40°C to +125°C operating temperature range per TI SBOS793H.

Does the INA2181A3IDGST require external gain-setting resistors?

No, the INA2181A3IDGST does not require external gain-setting resistors. It integrates a precision-matched thin-film resistor network configured for fixed 100 V/V gain, as indicated by the "A3" suffix. This eliminates resistor tolerance errors, reduces board space, and ensures stable gain performance with ≤20 ppm/°C drift over temperature.

How is bidirectional current sensing implemented on the INA2181A3IDGST?

Bidirectional sensing on the INA2181A3IDGST is achieved by applying a reference voltage (e.g., VS/2) to the REF1 and REF2 pins. A positive differential input (IN+ > IN–) produces an output above the REF voltage; a negative differential input produces an output below REF. This enables single-supply, single-ended ADC interfacing with full-scale utilization for both charge and discharge currents.

What package type and thermal characteristics apply to the INA2181A3IDGST?

The INA2181A3IDGST uses the 10-pin VSSOP (DGS) package, 3.0 mm × 4.9 mm, with an exposed thermal pad. Its junction-to-ambient thermal resistance (RθJA) is 177.3°C/W. The thermal pad may be left floating or connected to GND to improve heat dissipation-critical for sustained operation at 125°C ambient in enclosed power modules.

Can the INA2181A3IDGST operate with a 3.3-V supply while monitoring a 24-V bus?

Yes, the INA2181A3IDGST operates from 2.7 V to 5.5 V and supports input common-mode voltages up to +26 V-fully decoupled from the supply rail. When powered from 3.3 V, it accurately measures current through a shunt resistor placed between a 24-V bus and load, making it ideal for compact, mixed-voltage industrial controllers without auxiliary supplies.