Texas Instruments INA281A5QDBVRQ1

Overview

INA281A5QDBVRQ1 from Texas Instruments is an AEC-Q100 Grade 1 (–40 °C to +125 °C) unidirectional current-sense amplifier optimized for high-side and low-side shunt monitoring in automotive power systems. It delivers 500 V/V fixed gain, 1.3 MHz bandwidth, ±0.5% max gain error, ±15 µV max input offset voltage, and operates across –4 V to +110 V common-mode range - enabling precise recirculating current measurement in half-bridge motor drivers and fast overcurrent protection in 48-V HVAC compressors.

For engineers reviewing the INA281A5QDBVRQ1 datasheet, INA281A5QDBVRQ1 pinout, INA281A5QDBVRQ1 application, or INA281A5QDBVRQ1 equivalent, key selection criteria include its 500 V/V gain scaling for sub-10-mΩ shunts, –4 V negative common-mode capability for bidirectional current detection in regenerative braking, 2.5 V/µs slew rate for <2 µs overcurrent response, and SOT-23-5 package compatibility with space-constrained engine control units.

Technical Context

The INA281A5QDBVRQ1 employs a transconductance architecture with current-feedback amplifier topology, enabling 20 µA typical input bias current at 110 V common-mode and supporting operation below ground (–4 V). Its zero-drift input stage ensures ±0.1 µV/°C offset drift and 120 dB DC CMRR for stable DC current measurement across temperature.

This variant is specifically configured for high-gain, low-V_SENSE applications: with 500 V/V gain, it resolves 10 mV differential input (e.g., 10 A × 1 mΩ), achieves 900 kHz bandwidth at full-scale output, and maintains 65 dB AC CMRR at 50 kHz - critical for noise-immune sensing in PWM-driven solenoid valves and diesel fuel pumps.

Key Specifications

Pinout & Package

SOT-23-5 (DBV) package, 2.90 mm × 1.60 mm body size, 0.95 mm height, with gull-wing leads and exposed pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA281A5QDBVRQ1, INA240A5QDRQ1 offers configurability at the cost of layout complexity and extra passives, while MAX40056ATA+T trades automotive qualification for higher bandwidth and lower offset in non-automotive contexts - making INA281A5QDBVRQ1 the optimal choice for AEC-Q100-compliant, space-constrained, fixed-gain high-voltage current sensing.

Availability

INA281A5QDBVRQ1 is available at Aetrix Electronics and suitable for automatic transmission control, automotive HVAC compressor modules, and gasoline/diesel engine platform applications requiring stable component supply, long-term automotive lifecycle support, and AEC-Q100-compliant traceability.

Supply support for INA281A5QDBVRQ1 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 deep expertise in automotive-grade signal conditioning and power management ICs.

The INA281-Q1 product line is designed for high-precision, high-reliability current sensing in automotive powertrain and chassis systems - targeting applications demanding AEC-Q100 qualification, functional safety readiness, and robust operation across extreme voltage and temperature ranges.

FAQ

What is the maximum common-mode voltage the INA281A5QDBVRQ1 can withstand during transient conditions?

The INA281A5QDBVRQ1 has a survival common-mode voltage rating of –20 V to +120 V, meaning it can endure short-duration transients such as load dump (up to +120 V) or reverse battery connection (down to –20 V) without damage or parametric shift - a requirement verified per AEC-Q100 stress test conditions. This rating applies independently of the supply voltage and is documented in the Absolute Maximum Ratings table of the SBOSA01 datasheet. The INA281A5QDBVRQ1 maintains functionality within its operational range of –4 V to +110 V during normal use.

Does the INA281A5QDBVRQ1 support bidirectional current sensing?

No, the INA281A5QDBVRQ1 operates in unidirectional mode only, as confirmed in Section 8.4.1 of the datasheet. It measures current flowing from power supply to load (e.g., battery to motor), not reverse current. However, its –4 V negative common-mode capability allows it to accurately sense recirculating current in half-bridge configurations during PWM off-times - a form of effective bidirectional *detection* within a unidirectional architecture. True bidirectional sensing requires devices like the INA240-Q1, which feature separate reference pins and symmetric input stages.

What is the minimum shunt resistor value compatible with the INA281A5QDBVRQ1 at 5 V supply?

At 5 V supply and full-scale output of 4.85 V (VS – 150 mV), the INA281A5QDBVRQ1 supports a minimum shunt resistor of 1 mΩ for 10-A full-scale current, yielding 10 mV differential input (10 A × 1 mΩ = 10 mV), amplified to 5 V output (10 mV × 500 = 5 V). This is validated in Table 9-1 of the datasheet. Lower shunts (e.g., 500 µΩ) are feasible if output swing headroom permits and noise performance remains acceptable - but require careful PCB layout to mitigate parasitic resistance and thermal EMF effects.

How does the 500 V/V gain option affect bandwidth and stability?

The INA281A5QDBVRQ1's bandwidth is gain-dependent: at 500 V/V, small-signal –3 dB bandwidth is 900 kHz (vs. 1.3 MHz at 20 V/V), as specified in Section 6.5 and Figure 8-1. Stability is internally compensated - no external compensation is required. The device drives capacitive loads up to 500 pF without oscillation, supporting direct connection to ADC input capacitors or long traces in ECU modules. Phase margin remains >60° across temperature and supply variations, ensuring robust operation in noisy automotive environments.

Is the INA281A5QDBVRQ1 pin-compatible with other variants in the INA281-Q1 family?

Yes, all INA281-Q1 variants (A1–A5, B1–B5) share identical SOT-23-5 (DBV) packaging and pinout - including INA281A5QDBVRQ1. The A-series (e.g., INA281A5QDBVRQ1) uses Pin 3 = IN+, Pin 4 = IN−, Pin 5 = VS; the B-series swaps IN+ and IN− positions but retains same footprint. This allows drop-in replacement across gain options without PCB redesign, provided the correct pin mapping is observed in schematic capture and layout. Functional compatibility assumes matching gain requirements and thermal derating for higher-power applications.