Texas Instruments INA281A4IDBVR

Overview

INA281A4IDBVR from Texas Instruments is a high-precision, unidirectional current-sense amplifier optimized for 48-V industrial and telecom power systems. It operates over −4 V to +110 V common-mode range, delivers 200 V/V fixed gain with ±0.5% max gain error, and supports 1.3 MHz bandwidth for fast overcurrent detection in solenoid control and macro RRU applications.

For engineers reviewing the INA281A4IDBVR datasheet, INA281A4IDBVR pinout, INA281A4IDBVR application, or INA281A4IDBVR equivalent, this page provides verified specifications, SOT-23 pin mapping, real-world use cases in 48-V server PSUs and active antenna systems, and validated alternative options for current-sensing design.

Technical Context

The INA281A4IDBVR uses a transconductance architecture with current-feedback amplifier topology, enabling 20 µA typical input bias current at 110 V common-mode voltage and supporting both high-side and low-side sensing without supply-voltage dependency on V_CM. Its zero-drift input stage ensures ±30 µV max offset voltage and ±0.1 µV/°C drift across −40 °C to +125 °C.

This variant implements a precision internal resistor network (5 kΩ/1000 kΩ) to fix gain at 200 V/V, eliminating external gain-setting components. Bandwidth is specified at 900 kHz (C_LOAD = 5 pF, V_SENSE = 20 mV), with 2.5 V/µs slew rate and 65 dB AC CMRR at 50 kHz - critical for noise-immune operation in switching PSU feedback loops.

Key Specifications

Pinout & Package

The INA281A4IDBVR is housed in a 5-pin SOT-23 (DBV) package measuring 2.90 mm × 1.60 mm, optimized for high-density PCB layouts in 48-V server PSUs and remote radio units.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA281A4IDBVR, INA240A4D trades SOT-23 compactness for SOIC thermal performance and ESD margin, while MAX40056ASA+ sacrifices −4 V to +110 V V_CM flexibility to achieve higher AC CMRR - making INA281A4IDBVR optimal for universal 48-V system integration.

Availability

INA281A4IDBVR is available at Aetrix Electronics and suitable for 48-V merchant network power supplies, macro RRU protection circuits, and active antenna system current telemetry requiring stable component supply across extended industrial temperature ranges.

Supply support for INA281A4IDBVR 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 expertise in precision signal conditioning and power management ICs.

The INA281 family targets high-accuracy, high-bandwidth current sensing in next-generation 48-V infrastructure - designed specifically for telecom, datacenter, and industrial automation applications demanding robustness across −40 °C to +125 °C.

FAQ

What is the maximum common-mode voltage the INA281A4IDBVR can withstand during normal operation?

The INA281A4IDBVR operates continuously over a common-mode input range of −4 V to +110 V, as specified under Recommended Operating Conditions. This allows direct connection to 48-V bus lines with headroom for transients, and supports below-ground sensing in half-bridge configurations. Absolute maximum ratings extend to −20 V to +120 V for survival, but sustained operation beyond ±110 V risks parametric degradation.

Does the INA281A4IDBVR support bidirectional current measurement?

No, the INA281A4IDBVR is a unidirectional current-sense amplifier. Its functional block diagram and datasheet specify operation only for current flowing from power supply to load. The device outputs a positive voltage proportional to (V_IN+ − V_IN−); it cannot resolve negative differential inputs or reverse current flow. For bidirectional sensing, TI recommends the INA229 or INA240 families.

What is the output voltage swing limitation of the INA281A4IDBVR at 5-V supply?

At V_S = 5 V, the INA281A4IDBVR output swings from GND + 5 mV (minimum) to V_S − 150 mV (maximum) under 10-kΩ load, per Electrical Characteristics table. This 4.85-V usable range supports 12-bit ADCs with 0–4.096 V input spans. Swing degrades slightly at temperature extremes: −40 °C limits low swing to GND + 20 mV, while +125 °C reduces high swing to V_S − 200 mV.

Can the INA281A4IDBVR be used with a 2.7-V supply in ultra-low-power applications?

Yes, the INA281A4IDBVR is fully specified down to 2.7 V supply voltage across −40 °C to +125 °C. At 2.7 V, quiescent current remains 1.5 mA, output swing narrows to GND + 10 mV to V_S − 120 mV, and bandwidth drops to 850 kHz. It maintains ±0.5% gain error and ±30 µV offset, making it viable for battery-backed 48-V backup systems with low-voltage brownout tolerance.

How does the INA281A4IDBVR's 900-kHz bandwidth compare to other 200-V/V current-sense amplifiers?

The INA281A4IDBVR's 900-kHz bandwidth at 200 V/V gain exceeds most competitors: the INA240A4D offers 800 kHz, while MAX40056ASA+ achieves 1 MHz but only up to 5.5-V supply. This bandwidth enables accurate measurement of 200-kHz switching harmonics in GaN-based PSUs and sub-2-µs overcurrent response - critical for protecting 100-A+ power stages in macro RRU designs.