Texas Instruments INA181A3IDCKR

Overview

INA181A3IDCKR 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 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 - enabling precise motor control and battery monitoring in space-constrained industrial power systems.

For engineers reviewing the INA181A3IDCKR datasheet, INA181A3IDCKR pinout, INA181A3IDCKR application, or INA181A3IDCKR equivalent, this page delivers verified specifications, SC70-6 package layout, real-world use cases in solar inverters and lighting control, and two validated alternative parts with documented functional and application-level differences.

Technical Context

The INA181A3IDCKR implements a precision current-shunt monitor architecture with integrated matched resistor gain network (100 V/V), enabling accurate RTI measurement of differential voltages across sense resistors under common-mode voltages from –0.2 V to +26 V - independent of its 2.7–5.5 V supply rail. Its input stage supports bidirectional sensing via REF pin biasing.

It delivers 150 kHz small-signal bandwidth and 2 V/µs slew rate for fast transient response in fault detection and PWM-driven loads, while maintaining ±1% max gain error and 1 µV/°C max offset drift over temperature - critical for stable closed-loop current regulation in motor drives and battery management.

Key Specifications

Pinout & Package

The INA181A3IDCKR is packaged in a 6-pin SC70 (DCK) footprint measuring 2.00 mm × 2.10 mm, optimized for high-density PCB layouts and thermal performance (R_θJA = 188°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA181A3IDCKR, INA240A3IDR offers superior voltage range and precision but demands PCB redesign, while MAX40056ATA+T matches gain and improves size efficiency at the cost of slightly reduced bandwidth - making each suitable for distinct mechanical and electrical constraints.

Availability

INA181A3IDCKR is available at Aetrix Electronics and suitable for motor control, battery monitoring, and solar inverter applications requiring stable component supply, long-term lifecycle support, and traceable sourcing for industrial OEM programs.

Supply support for INA181A3IDCKR 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 INA181 family was designed specifically for cost-optimized, high-accuracy bidirectional current sensing in industrial and automotive power systems - delivering integrated gain, wide common-mode operation, and robust thermal performance in compact packages.

FAQ

What is the exact gain setting of INA181A3IDCKR and how is it implemented?

The INA181A3IDCKR has a fixed gain of 100 V/V, achieved through an internal laser-trimmed matched resistor network. This eliminates external gain-setting components, reduces board area, and ensures ±1% maximum gain error across temperature. The "A3" suffix in the part number explicitly denotes the 100 V/V variant per TI's INAx181 device comparison table.

Can INA181A3IDCKR measure current in both directions, and what is required to enable bidirectional operation?

Yes, INA181A3IDCKR supports true bidirectional current sensing. To enable it, apply a DC bias voltage (e.g., VS/2 = 2.5 V for 5-V supply) to the REF pin. A positive differential input (IN+ > IN−) produces OUT > VREF; a negative differential input produces OUT < VREF. This allows single-supply systems to resolve current flow direction without external level-shifting circuitry.

What is the maximum common-mode voltage the INA181A3IDCKR can handle, and does it depend on the supply voltage?

The INA181A3IDCKR 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 means it can accurately sense current on a 24-V bus while powered from a 3.3-V rail - a key advantage over conventional op-amps and enabling direct high-side sensing without auxiliary supplies or isolation.

How does the bandwidth of INA181A3IDCKR compare to other variants in the INAx181 family?

The INA181A3IDCKR has a small-signal bandwidth of 150 kHz (measured at C_LOAD = 10 pF), which is lower than the A1 (350 kHz) and A2 (210 kHz) variants but higher than the A4 (105 kHz). This trade-off reflects the inverse relationship between gain and bandwidth in the fixed-gain architecture - making the A3 optimal for applications needing 100× scaling with sufficient speed for 10–15 kHz PWM systems.

Is the SC70-6 package of INA181A3IDCKR compatible with standard reflow profiles, and what thermal considerations apply?

Yes, the SC70-6 (DCK) package of INA181A3IDCKR is compatible with standard lead-free reflow profiles. Its thermal resistance is R_θJA = 188°C/W (JEDEC JESD51-2), so at 260 µA quiescent current and 5 V supply, self-heating is negligible (<0.3°C). For high-ambient environments (>85°C), ensure ≥100 mm² copper pour under the exposed pad (if used) and avoid routing high-current traces nearby to maintain accuracy.