Texas Instruments INA181A4IDCKR

Overview

INA181A4IDCKR from Texas Instruments is a single-channel, bidirectional current-sense amplifier optimized for high-accuracy, low-power current monitoring in both high-side and low-side configurations. It features 200 V/V fixed gain, –0.2 V to +26 V input common-mode range, ±500 µV max offset at 12 V VCM, 105 kHz bandwidth, and 2 V/µs slew rate-enabling precise motor control and battery monitoring in 2.7–5.5 V systems.

For engineers reviewing the INA181A4IDCKR datasheet, INA181A4IDCKR pinout, INA181A4IDCKR application, or INA181A4IDCKR equivalent, this page delivers verified specifications, SC70-6 package layout, real-world use cases in solar inverters and power management, and two validated alternative parts with documented functional and application-level differences.

Technical Context

The INA181A4IDCKR implements a precision current-shunt monitor architecture with an integrated 200 V/V matched-resistor gain network, enabling accurate RTI (referred-to-input) current measurement independent of supply voltage. Its proprietary topology supports operation with common-mode voltages exceeding VS-up to +26 V-while maintaining ±1% gain error and 1 µV/°C offset drift across –40°C to +125°C.

It operates as a closed-loop, rail-to-rail output amplifier with reference-controlled bidirectional sensing: VOUT = GAIN × (IN+ − IN−) + VREF. The SC70-6 package integrates all signal paths for minimal parasitic coupling, supporting stable performance with up to 1 nF capacitive load and 260 µA quiescent current.

Key Specifications

Pinout & Package

The INA181A4IDCKR is housed in a 6-pin SC70 package (2.00 mm × 2.10 mm), optimized for space-constrained PCB layouts and thermal performance in high-density power stages.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA240A4D and MAX40056ASA+T, the INA181A4IDCKR offers the lowest quiescent current (260 µA) and smallest SC70-6 footprint-making it optimal for space- and power-constrained 24-V industrial controls where bus voltage stays ≤26 V and bandwidth ≥105 kHz suffices.

Availability

INA181A4IDCKR is available at Aetrix Electronics and suitable for motor control, battery monitoring, and solar inverter applications requiring stable component supply, extended temperature support (–40°C to +125°C), and high-accuracy bidirectional current sensing.

Supply support for INA181A4IDCKR 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, embedded processing, and connectivity technologies, with decades of expertise in precision signal conditioning and power management ICs.

The INA181 family targets cost-optimized, high-accuracy current sensing in industrial, automotive, and computing power systems-designed to replace discrete op-amp + resistor solutions with integrated, temperature-stable gain and wide common-mode operation.

FAQ

What is the maximum common-mode voltage supported by the INA181A4IDCKR?

The INA181A4IDCKR 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 bus rails without external level-shifting. The specification is validated across –40°C to +125°C and applies to both IN+ and IN− pins simultaneously per the datasheet's Recommended Operating Conditions table.

Does the INA181A4IDCKR require external gain-setting resistors?

No, the INA181A4IDCKR does not require external gain-setting resistors. It integrates a factory-trimmed, matched resistor network that fixes the gain at 200 V/V. This eliminates resistor matching errors, reduces PCB area, improves temperature stability (gain error drift ≤20 ppm/°C), and ensures ±1% total gain error across temperature-confirmed in Section 6.5 Electrical Characteristics of the SBOS793H datasheet.

Can the INA181A4IDCKR measure bidirectional current, and how is polarity determined?

Yes, the INA181A4IDCKR supports bidirectional current measurement via the REF pin. When VREF is set to mid-supply (e.g., 2.5 V), positive differential input (IN+ > IN−) produces VOUT > VREF, while negative differential input (IN+ < IN−) yields VOUT < VREF. The output equation VOUT = 200 × (IN+ − IN−) + VREF enables unambiguous direction detection-critical for regenerative braking and battery charging circuits.

What is the bandwidth and slew rate of the INA181A4IDCKR, and how do they affect system performance?

The INA181A4IDCKR has a small-signal bandwidth of 105 kHz (for A4 gain variant) and a large-signal slew rate of 2 V/µs. These specs allow accurate capture of fast current transients-such as motor startup surges or short-circuit events-in real time. For example, at 200 V/V gain, a 10-mV step input produces a 2-V output step, fully settled in under 1 µs, enabling timely fault response in safety-critical power stages.

Is the INA181A4IDCKR compatible with low-voltage microcontrollers operating at 3.3 V?

Yes, the INA181A4IDCKR is fully compatible with 3.3 V microcontrollers. It operates from 2.7 V to 5.5 V, and its rail-to-rail output swings to within 30 mV of VS and 5 mV of GND. With VS = 3.3 V and VREF = 1.65 V, the output spans ~1.6 V to ~3.25 V-well within the input range of most 3.3 V ADCs and comparators, eliminating need for level-shifting circuitry.