Texas Instruments INA281B3QDBVRQ1

Overview

INA281B3QDBVRQ1 from Texas Instruments is an AEC-Q100 Grade 1 (–40 °C to +125 °C) unidirectional current-sense amplifier optimized for automotive high-side and low-side shunt monitoring. It delivers 100 V/V fixed gain, ±0.5% max gain error, ±55 µV typical input offset voltage, 1.3 MHz bandwidth, and operates from –4 V to +110 V common-mode range - enabling precise recirculating current measurement in half-bridge motor drivers and solenoid control modules.

For engineers reviewing the INA281B3QDBVRQ1 datasheet, INA281B3QDBVRQ1 pinout, INA281B3QDBVRQ1 application, or INA281B3QDBVRQ1 equivalent, key selection criteria include its 100 V/V gain accuracy over temperature, survival up to +120 V common-mode, 2.5 V/µs slew rate for fast overcurrent response, and SOT-23-5 package compatibility with space-constrained automotive PCB layouts.

Technical Context

The INA281B3QDBVRQ1 uses a transconductance architecture with current-feedback amplifier topology to achieve 20 µA typical input bias current at 110 V common-mode and maintain 120 dB DC CMRR. Its zero-drift input stage ensures stable offset performance across –40 °C to +125 °C, while the internal resistor network fixes gain at exactly 100 V/V without external components.

This variant supports unidirectional current sensing only, with output swing limited to GND + 5 mV (min) and VS – 70 mV (min) under load. Its 1.3 MHz bandwidth applies specifically at 100 V/V gain with 40 mV differential input, per TI SBOSA01 specification table.

Key Specifications

Pinout & Package

SOT-23-5 (DBV) package: 2.90 mm × 1.60 mm body, 0.95 mm height, gull-wing leads, RoHS-compliant, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA240A3QDR and MAX40056ATA+T, the INA281B3QDBVRQ1 uniquely combines AEC-Q100 Grade 1 operation, 110 V common-mode capability, and ±0.1 µV/°C offset drift - making it the only option qualified for precision high-voltage current sensing in ASIL-B transmission and engine control modules.

Availability

INA281B3QDBVRQ1 is available at Aetrix Electronics and suitable for automatic transmission control, HVAC compressor modules, valve/motor actuators, and gasoline & diesel engine platforms requiring stable component supply across extended automotive production lifecycles.

Supply support for INA281B3QDBVRQ1 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 automotive-grade IC design and manufacturing expertise.

The INA281-Q1 product line delivers high-precision, high-voltage current sensing for functional-safety-critical automotive subsystems - targeting transmission, powertrain, chassis, and electrification applications demanding AEC-Q100 reliability and ISO 26262 support.

FAQ

What is the maximum common-mode voltage the INA281B3QDBVRQ1 can withstand continuously?

The INA281B3QDBVRQ1 operates continuously within a common-mode voltage range of –4 V to +110 V. Its survival rating extends to –20 V to +120 V, meaning it can tolerate brief transients at those extremes without damage. This makes the INA281B3QDBVRQ1 suitable for direct connection to 48 V mild-hybrid battery rails and high-side motor drive nodes where voltage spikes exceed nominal bus levels.

Does the INA281B3QDBVRQ1 support bidirectional current measurement?

No, the INA281B3QDBVRQ1 is designed exclusively for unidirectional current sensing. It measures current flowing from the power source to the load only - not reverse or regenerative current. For bidirectional applications such as motor braking or energy recovery, a separate device like the INA229 or INA240 with symmetric input architecture is required. The INA281B3QDBVRQ1's internal topology does not support negative differential input interpretation.

What is the output voltage swing limitation of the INA281B3QDBVRQ1 at 5 V supply?

At VS = 5 V, the INA281B3QDBVRQ1 output swings from a minimum of GND + 5 mV to a maximum of VS – 70 mV (i.e., 4.93 V), under 10 kΩ load and –40 °C to +125 °C conditions. This 4.88 V usable range ensures compatibility with 5 V ADC references while maintaining linearity. The INA281B3QDBVRQ1's rail-sparing output stage avoids clipping during fast transients when paired with appropriate shunt and gain selection.

How does the 100 V/V gain of the INA281B3QDBVRQ1 affect shunt resistor selection?

With 100 V/V gain, the INA281B3QDBVRQ1 converts 10 mV across the shunt into 1 V output - enabling use of very low-value shunts (e.g., 1 mΩ for 10 A full-scale). Per TI's Table 9-1, this reduces power dissipation by 90% versus a 20 V/V variant at the same current, critical for thermally constrained modules like HVAC compressors. The INA281B3QDBVRQ1's low offset ensures accuracy remains intact even at these small differential voltages.

Is the INA281B3QDBVRQ1 pin-compatible with other variants in the INA281-Q1 family?

Yes - all INA281-Q1 variants (A1–A5 and B1–B5) share identical SOT-23-5 (DBV) packaging and pinout. The INA281B3QDBVRQ1 uses the B-version pin configuration (IN+ on Pin 4, IN− on Pin 5), which differs from the A-version (IN+ on Pin 3, IN− on Pin 4), but both are mechanically interchangeable on the same footprint. Designers must verify schematic connectivity matches the chosen variant's pin mapping before layout release.