Texas Instruments INA285AIDGKT

Overview

INA285AIDGKT 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, and 140 dB CMRR, enabling accurate low-side and high-side current measurement in telecom power supplies and solar inverter DC-link monitoring.

For engineers reviewing the INA285AIDGKT datasheet, INA285AIDGKT pinout, INA285AIDGKT application, or INA285AIDGKT equivalent, key selection criteria include its wide common-mode range, ultra-low offset drift (0.3 µV/°C), 2 kHz effective bandwidth, rail-to-rail output swing capability, and compatibility with unidirectional/bidirectional sensing topologies using REF1/REF2 reference pins.

Technical Context

The INA285AIDGKT employs a zero-drift chopper-stabilized amplifier architecture with switched-capacitor input stage, enabling stable dc accuracy and high CMRR despite extreme common-mode transients. Its internal reference divider network allows flexible output biasing via REF1 and REF2 pins, supporting ground-referenced, V+-referenced, or externally biased operation.

This device operates from a single 2.7 V to 18 V supply, draws ≤900 µA quiescent current, and maintains specified performance over –40°C to +125°C. The 1000 V/V gain is factory-trimmed and temperature-compensated, with ±1.6% max gain error across temperature and supply voltage variations.

Key Specifications

Pinout & Package

VSSOP-8 package (3.00 mm × 3.00 mm body size) with exposed thermal pad; RoHS-compliant, lead-free finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA282AIDGKT and INA240AIDR, the INA285AIDGKT provides the highest gain (1000 V/V) and lowest offset drift (0.3 µV/°C) in the family, making it uniquely suited for ultra-low-shunt-voltage, high-accuracy DC current measurement where thermal stability and minimal power loss dominate design priorities.

Availability

INA285AIDGKT is available at Aetrix Electronics and suitable for telecom power supplies, solar inverter DC-link monitoring, automotive battery management, and industrial motor drive applications requiring stable component supply and long-term production continuity.

Supply support for INA285AIDGKT 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, data converters, and power management ICs.

The INA28x product line was developed specifically for high-accuracy, wide common-mode current sensing in harsh electrical environments-including telecom infrastructure, renewable energy systems, and automotive electrification platforms.

FAQ

What is the maximum common-mode voltage the INA285AIDGKT can withstand?

The INA285AIDGKT supports a common-mode input voltage range of –14 V to +80 V, meaning it can accurately measure shunt voltage drops while referenced to buses as low as –14 V (e.g., reverse battery conditions) or as high as +80 V (e.g., automotive load-dump transients). This rating is absolute and does not depend on supply voltage, allowing operation from 2.7 V up to 18 V while maintaining full common-mode tolerance. The INA285AIDGKT achieves this via proprietary input stage architecture that isolates the sensing core from rail extremes.

How does the REF1 and REF2 pin configuration affect output behavior in the INA285AIDGKT?

The REF1 and REF2 pins of the INA285AIDGKT form an internal resistive divider that sets the output's quiescent voltage. When both are tied to GND, the output rests near 0 V for zero differential input (unidirectional low-side mode). When tied to V+, the output rests near V+ (unidirectional high-side diagnostic mode). When biased to an external reference (e.g., 2.048 V), the INA285AIDGKT enables bidirectional sensing with output centered at that voltage. The INA285AIDGKT requires the average of REF1 and REF2 to remain between GND and 9 V for proper operation.

Can the INA285AIDGKT be used for bidirectional current sensing, and what design considerations apply?

Yes, the INA285AIDGKT supports true bidirectional current sensing by configuring REF1 and REF2 to set a mid-supply output quiescent point (e.g., V+/2). With 1000 V/V gain, a ±10 mV shunt voltage produces ±10 V output swing-requiring ≥12 V supply for full range. Layout must minimize imbalance between +IN and –IN traces, and REF1/REF2 routing should be symmetrical and low-impedance. The INA285AIDGKT's 140 dB CMRR ensures accurate differential measurement even under high common-mode noise typical in motor drive or inverter applications.

What is the effective bandwidth of the INA285AIDGKT, and how does it impact dynamic response?

The INA285AIDGKT has an effective bandwidth of 2 kHz, defined as the frequency at which small-signal gain drops by 3 dB. This bandwidth reflects its switched-capacitor zero-drift architecture and limits usable signal content to frequencies below ~2 kHz. Step responses show settling within 15 µs after common-mode disturbances, but large differential steps exhibit overshoot due to internal clock phase dependency. For the INA285AIDGKT, this makes it ideal for DC and slowly varying currents (e.g., battery charge/discharge monitoring) but unsuitable for PWM current reconstruction above 1 kHz.

Does the INA285AIDGKT require external components for ESD or transient protection?

No-within its rated common-mode range (–14 V to +80 V), the INA285AIDGKT incorporates internal protection sufficient for standard automotive (ISO 7637-2) and telecom (GR-1089) transients. Its ±2000 V HBM ESD rating meets JEDEC JS-001 requirements. However, exposure to transients exceeding +80 V or –14 V (e.g., lightning-induced surges) requires external Zener-based clamping. The INA285AIDGKT's input structure is sensitive to series resistance, so external current-limiting resistors degrade gain accuracy and are not recommended unless absolutely necessary for overvoltage fault containment.