Texas Instruments INA181A1IDCKR

Overview

INA181A1IDCKR from Texas Instruments is a single-channel, bidirectional current-sense amplifier optimized for high-accuracy, low-power sensing in both high-side and low-side configurations. It features 20 V/V fixed gain, ±150 µV max input offset at 0 V common-mode, 350 kHz bandwidth, and operates from 2.7 V to 5.5 V supply across –40°C to +125°C - enabling precise motor phase current monitoring in compact industrial drives.

For engineers reviewing the INA181A1IDCKR datasheet, INA181A1IDCKR pinout, INA181A1IDCKR application, or INA181A1IDCKR equivalent, this page delivers verified electrical specs, SC70 package layout, real-world use cases in battery management and solar inverters, and two validated alternative parts with documented functional trade-offs.

Technical Context

The INA181A1IDCKR implements a precision current-shunt monitor architecture with integrated matched resistor gain network (20 V/V), enabling accurate RTI voltage measurement 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 and maintains CMRR ≥84 dB over temperature.

It delivers 2 V/µs slew rate and rail-to-rail output swing (within 30 mV of VS and 5 mV of GND), ensuring fast transient response for fault detection and closed-loop control. Quiescent current remains ≤260 µA, making it suitable for always-on power monitoring in energy-constrained systems.

Key Specifications

Pinout & Package

The INA181A1IDCKR is housed in a 6-pin SC70 package (2.00 mm × 2.10 mm), optimized for space-constrained PCB layouts while maintaining 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 INA240A1D and MAX40056ASA+, the INA181A1IDCKR uniquely balances ultra-low power (260 µA), wide common-mode (26 V), SC70 size, and factory-trimmed 20 V/V gain - making it optimal for space- and energy-constrained industrial and renewable energy systems requiring no external gain components.

Availability

INA181A1IDCKR 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 guaranteed traceable sourcing.

Supply support for INA181A1IDCKR 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 belongs to TI's INAx181 family of cost-optimized, bidirectional current-sense amplifiers designed for high-accuracy, low-power current monitoring in industrial motor drives, energy systems, and portable electronics.

FAQ

What is the maximum common-mode voltage supported by the INA181A1IDCKR?

The INA181A1IDCKR 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 attenuation. The specification is guaranteed across the full –40°C to +125°C operating temperature range, and the INA181A1IDCKR maintains functionality even when VCM exceeds VS - a key differentiator from general-purpose op-amps.

Does the INA181A1IDCKR require external gain-setting resistors?

No, the INA181A1IDCKR integrates a factory-trimmed, matched resistor network for fixed 20 V/V gain - eliminating external resistors, layout sensitivity, and thermal drift errors associated with discrete gain networks. This simplifies design, improves production yield, and ensures consistent performance across units. The gain is laser-trimmed during manufacturing and specified as ±1% maximum error over temperature, which the INA181A1IDCKR achieves without user calibration.

Can the INA181A1IDCKR measure bidirectional current with a single supply?

Yes, the INA181A1IDCKR supports true bidirectional current sensing using a single 2.7–5.5 V supply by applying a reference voltage (e.g., VS/2) to the REF pin. A positive differential input produces V_OUT > V_REF; a negative differential input produces V_OUT < V_REF. This capability is intrinsic to the INA181A1IDCKR's architecture and requires no additional components - enabling compact, low-cost implementations for battery charge/discharge monitoring and H-bridge current feedback.

What is the typical output swing capability of the INA181A1IDCKR?

The INA181A1IDCKR provides rail-to-rail output swing: within 30 mV of VS and 5 mV of GND under 10 kΩ load conditions. This maximizes usable dynamic range for ADC interfacing - for example, with a 5 V supply, the output spans ~0.005 V to 4.97 V. The specification holds across –40°C to +125°C and is critical for preserving resolution in 12-bit+ data acquisition systems, directly contributing to the accuracy advantage of the INA181A1IDCKR in precision sensing applications.

How does the INA181A1IDCKR handle high-frequency noise on the sense resistor?

The INA181A1IDCKR achieves ≥84 dB common-mode rejection ratio (CMRR) up to 100 kHz, effectively suppressing high-frequency noise coupled onto the sense resistor from adjacent switching nodes or EMI sources. Its internal topology rejects common-mode transients without requiring external filtering that would degrade bandwidth. This CMRR performance is measured and guaranteed for the INA181A1IDCKR across temperature and supply variations - ensuring robust operation in electrically noisy motor drive and inverter environments.