Texas Instruments INA281A3QDBVRQ1

Overview

INA281A3QDBVRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive current-sense amplifier designed for unidirectional high-side or low-side shunt monitoring in systems with common-mode voltages from –4 V to +110 V. It delivers 100 V/V fixed gain, ±0.5% max gain error, ±30 µV max input offset voltage (typical ±30 µV), and 1.3 MHz bandwidth - enabling precise, fast-response current measurement in engine control units and motor actuator protection circuits.

For engineers reviewing the INA281A3QDBVRQ1 datasheet, INA281A3QDBVRQ1 pinout, INA281A3QDBVRQ1 application, or INA281A3QDBVRQ1 equivalent, key selection criteria include its –4 V to +110 V operational common-mode range, 100 V/V gain accuracy over –40 °C to +125 °C, 2.5 V/µs slew rate for overcurrent detection, and SOT-23-5 package compatibility with space-constrained automotive PCB layouts.

Technical Context

The INA281A3QDBVRQ1 uses a transconductance architecture with current-feedback amplifier topology, enabling low input bias current (20 µA typical at 110 V VCM) and wide common-mode operation independent of supply voltage. Its zero-drift input stage ensures stable offset performance across temperature, supporting accurate low-VSENSE measurements down to 40 mV full-scale output.

This variant implements a fixed 100 V/V gain via precision internal resistor network (10 kΩ/1000 kΩ ratio), delivering 1000 kHz bandwidth at 40 mV VSENSE input and maintaining ≥120 dB DC CMRR. Functional safety documentation is available to support ISO 26262 ASIL-B system integration in transmission and HVAC compressor modules.

Key Specifications

Pinout & Package

SOT-23-5 package (2.90 mm × 1.60 mm body size) with DBV pinout variant A (IN+ on Pin 3, IN– on Pin 4, Vs on Pin 5).

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA281A3QDBVRQ1, INA240A3QDRQ1 trades bandwidth for enhanced negative common-mode capability, while MAX40056ATA+T offers higher speed but reduced temperature grade - making INA281A3QDBVRQ1 optimal for under-hood powertrain applications demanding both speed and Grade 1 thermal robustness.

Availability

INA281A3QDBVRQ1 is available at Aetrix Electronics and suitable for automatic transmission control, automotive HVAC compressor modules, valve/motor actuator monitoring, gasoline & diesel engine platforms, and pump current sensing requiring stable component supply across automotive production lifecycles.

Supply support for INA281A3QDBVRQ1 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 automotive-grade signal conditioning and power management ICs.

The INA281-Q1 product line delivers high-precision, AEC-Q100-qualified current-sense amplifiers optimized for real-time motor, solenoid, and battery current monitoring in safety-critical automotive powertrain and chassis systems.

FAQ

What is the maximum common-mode voltage the INA281A3QDBVRQ1 can handle during normal operation?

The INA281A3QDBVRQ1 operates continuously within a common-mode voltage range of –4 V to +110 V. This specification is validated across the full –40 °C to +125 °C temperature range and enables reliable use in high-side configurations on 48 V or 12 V battery rails. The device also survives transient conditions from –20 V to +120 V without damage, per absolute maximum ratings in the official datasheet.

Does the INA281A3QDBVRQ1 support bidirectional current sensing?

No, the INA281A3QDBVRQ1 is specified for unidirectional current sensing only. Its functional block diagram and application diagrams confirm operation with current flowing from power supply to load. The device does not support reverse-current detection or true bidirectional measurement - for such use cases, TI recommends the INA229 or similar bidirectional alternatives.

What is the typical input offset voltage for the INA281A3QDBVRQ1, and how does it affect low-current measurement?

The INA281A3QDBVRQ1 has a typical input offset voltage of ±30 µV, with a maximum of ±250 µV over temperature. At 100 V/V gain, this translates to ±25 mV output-referred error - meaning accurate measurement of currents below ~250 mA requires careful shunt resistor selection (e.g., ≥100 mΩ) to ensure the sensed voltage exceeds the offset contribution. The zero-drift architecture minimizes drift to ±0.1 µV/°C, preserving accuracy across thermal cycling.

Can the INA281A3QDBVRQ1 be used with a 3.3 V supply voltage?

Yes, the INA281A3QDBVRQ1 operates from 2.7 V to 20 V, so 3.3 V is fully supported. At 3.3 V supply, the output swings from GND + 5 mV to VS – 150 mV (i.e., up to 3.15 V), maintaining full dynamic range for 12-bit or 16-bit MCU ADCs. Quiescent current remains 1.5 mA, and bandwidth is preserved at 1000 kHz for VSENSE ≥40 mV, as confirmed in Section 6.5 of the SBOSA01 datasheet.

Is the INA281A3QDBVRQ1 pin-compatible with other variants in the INA281-Q1 family?

Yes, all INA281-Q1 variants - including INA281A1QDBVRQ1 through INA281A5QDBVRQ1 - share identical SOT-23-5 (DBV) packaging and pinout. The INA281A3QDBVRQ1 uses the "A" variant pin configuration (IN+ on Pin 3, IN– on Pin 4, Vs on Pin 5), matching all other A-suffix parts. This allows direct substitution within the same gain family without PCB layout changes, provided the system's VSENSE and bandwidth requirements align with the 100 V/V option.