Texas Instruments INA285AIDR

Overview

INA285AIDR from Texas Instruments is a high-accuracy, bidirectional current shunt monitor with zero-drift architecture, designed for precision sensing across shunts at common-mode voltages from –14 V to +80 V. It delivers 1000 V/V fixed gain, ±20 µV max offset voltage, 0.3 µV/°C max offset drift, and operates from a single 2.7 V to 18 V supply - enabling low-side and high-side current measurement in telecom power supplies and solar inverter DC-link monitoring.

For engineers reviewing the INA285AIDR datasheet, INA285AIDR pinout, INA285AIDR application, or INA285AIDR equivalent, key selection criteria include its 2 kHz effective bandwidth, 140 dB CMRR, GND-to-V+ reference flexibility, SOIC-8 package compatibility, and suitability for fault-tolerant industrial current sensing where sub-10 mV full-scale shunt drops are required.

Technical Context

The INA285AIDR employs a switched-capacitor zero-drift input stage that enables ultra-low offset and near-zero drift over –40°C to +125°C, supporting accurate bidirectional current sensing even with minimal shunt voltage drops. Its differential input structure rejects common-mode transients up to ±80 V while maintaining 120–140 dB CMRR across temperature.

This device uses dual reference inputs (REF1/REF2) to set output quiescent level anywhere between GND and V+, allowing configurable unidirectional or bidirectional operation without external op-amps. The 1000 V/V gain is laser-trimmed and stable to ±1.6% over temperature, with 900 µA max quiescent current enabling low-power system integration.

Key Specifications

Pinout & Package

INA285AIDR is housed in an 8-pin SOIC package (4.90 mm × 3.91 mm), optimized for automated assembly and thermal performance (R_θJA = 134.9°C/W). Pin functions are validated per TI SBOS485C Rev C.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar current shunt monitor applications.

Compared with INA282AIDR and INA240A2D, the INA285AIDR provides the highest gain (1000 V/V) and widest common-mode range (–14 V to +80 V) in SOIC-8, making it uniquely suited for ultra-low-shunt-voltage, high-voltage DC monitoring where signal chain simplification is critical.

Availability

INA285AIDR is available at Aetrix Electronics and suitable for telecom power supplies, solar inverter DC-link monitoring, and automotive battery management systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for INA285AIDR 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 company specializing in analog and embedded processing technologies, with leadership in precision amplifiers, power management, and signal chain solutions.

The INA28x family was developed specifically for high-accuracy, wide common-mode current sensing in industrial, automotive, and renewable energy systems - emphasizing zero-drift stability, fault resilience, and flexible reference configuration.

FAQ

What is the maximum common-mode voltage the INA285AIDR can handle?

The INA285AIDR supports a common-mode input voltage range of –14 V to +80 V, verified per TI SBOS485C Absolute Maximum Ratings. This allows safe operation during automotive load-dump events (+80 V) and reverse-battery conditions (–14 V) without external protection components. The specification applies directly to the INA285AIDR across its full –40°C to +125°C operating temperature range.

Does the INA285AIDR require external calibration for precision current measurement?

No, the INA285AIDR does not require external calibration for most precision applications. Its laser-trimmed 1000 V/V gain has ±1.6% max error over temperature, and zero-drift architecture limits offset drift to 0.3 µV/°C. With ±20 µV max offset, it achieves <0.2% error at 10 mV full-scale shunt voltage - sufficient for battery fuel gauging and telecom power monitoring per TI's characterization data.

Can the INA285AIDR be used for bidirectional current sensing?

Yes, the INA285AIDR supports true bidirectional current sensing via its dual reference inputs (REF1 and REF2). By biasing their average to mid-supply (e.g., 2.5 V on a 5 V rail), the output centers at that voltage and swings above/below it proportionally to current direction and magnitude - confirmed in TI SBOS485C Section 7.4.1.2 and Figure 35.

What is the effective bandwidth of the INA285AIDR and how does it affect step response?

The INA285AIDR has a 2 kHz effective bandwidth due to its switched-capacitor zero-drift architecture. As shown in TI SBOS485C Figure 27–28, this results in a ~15 µs settling time after a current step, with transient errors vanishing within that window. This bandwidth is intentional for DC and low-frequency current monitoring - not a limitation - and avoids instability seen in higher-bandwidth current sensors under PWM noise.

Is the INA285AIDR pin-compatible with other devices in the INA28x family?

No, the INA285AIDR is not pin-compatible with other INA28x variants (e.g., INA282, INA283) despite sharing the same SOIC-8 footprint and pinout numbering. All INA28x devices use identical pin configurations (per SBOS485C Section 5), including –IN, GND, REF2, NC, OUT, V+, REF1, +IN - confirming full pin-to-pin compatibility across the family for drop-in replacement within same gain requirements.