Texas Instruments INA381A3IDGSR

Overview

INA381A3IDGSR from Texas Instruments is a 26-V, high-speed current-sense amplifier with integrated comparator, designed for overcurrent detection in high-side and low-side shunt configurations. It delivers 100 V/V gain, ±150 µV max input offset at 0 V common-mode, 150 kHz bandwidth, and <10 µs total overcurrent response time. It operates from 2.7 V to 5.5 V supply and supports –0.2 V to +26 V input common-mode voltage - enabling use in merchant server PSUs and cordless power tools.

For engineers reviewing the INA381A3IDGSR datasheet, INA381A3IDGSR pinout, INA381A3IDGSR application, or INA381A3IDGSR equivalent, this page provides verified functional context, validated pin roles, confirmed package mapping (VSSOP-10), real-world timing performance (400 ns comparator propagation delay), and two rigorously cross-checked alternative parts with documented technical and application differences.

Technical Context

The INA381A3IDGSR implements a zero-drift amplifier topology with integrated open-drain comparator, supporting both transparent and latched alert modes via the RESET pin. Its input stage tolerates –0.2 V to +26 V common-mode voltage independent of its 2.7–5.5 V supply rail, enabling direct high-side sensing on 12 V or 24 V buses without level-shifting.

It features 100 V/V fixed gain (A3 variant), 50 mV comparator hysteresis, and a 150 kHz small-signal bandwidth. The VOUT output drives the CMPIN input directly for threshold comparison, while CMPREF accepts an external reference to set the overcurrent trip point - enabling precise, adjustable current-limiting with <2 µs large-signal alert response.

Key Specifications

Pinout & Package

The INA381A3IDGSR is housed in a 10-pin VSSOP package (3.00 mm × 3.00 mm body size) with exposed thermal pad connected to GND. Pin 6 is NC (no internal connection) and may be left floating, grounded, or tied to VS+ per layout requirements.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA381A3IDGSR, the IDSGR offers identical functionality in a smaller package but requires revised thermal and routing design, while the INA219BIDR trades speed and analog alert capability for digital interface and higher DC accuracy - making it unsuitable for real-time fault containment.

Availability

INA381A3IDGSR is available at Aetrix Electronics and suitable for merchant server PSUs, DC-input BLDC motor drives, and cordless power tool designs requiring stable component supply, guaranteed long-term sourcing, and production-ready traceability.

Supply support for INA381A3IDGSR 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, power management, and signal chain solutions.

The INA381 product line delivers integrated current-sense amplifiers with onboard comparators for real-time overcurrent protection - designed specifically for high-reliability, fast-response applications in server infrastructure, motor control, and portable power systems.

FAQ

What is the maximum common-mode input voltage supported by the INA381A3IDGSR?

The INA381A3IDGSR supports a common-mode input voltage range of –0.2 V to +26 V, independent of its 2.7 V to 5.5 V supply voltage. This allows direct high-side sensing on 24 V bus rails without level-shifting circuitry. The device remains functional and undamaged even when the supply is removed while 26 V is present on IN+ and IN–, as confirmed in Absolute Maximum Ratings.

How does the RESET pin configure alert behavior in the INA381A3IDGSR?

The RESET pin on the INA381A3IDGSR selects between transparent and latched alert modes: logic high enables transparent mode (ALERT follows input state in real time), while logic low enables latched mode (ALERT stays asserted until RESET is pulsed high). This dual-mode flexibility supports both continuous monitoring and fault-hold applications - a key differentiator from basic comparators.

What is the gain accuracy and temperature drift specification for the INA381A3IDGSR?

The INA381A3IDGSR has a gain error of ±1% maximum at 25°C and gain error drift of 20 ppm/°C maximum over –40°C to +125°C. These values are explicitly specified in the Electrical Characteristics table for the A3 variant (100 V/V) and are measured under defined test conditions including V_OUT = 0.5 V to V_S – 0.5 V.

Can the INA381A3IDGSR be used in low-side current sensing applications?

Yes, the INA381A3IDGSR is fully qualified for low-side current sensing, with ±150 µV maximum input offset voltage at 0 V common-mode - optimized for accuracy in ground-referenced shunt configurations. Its ability to reject ground noise and maintain low offset makes it especially effective in motor drive and battery-monitoring applications where the shunt resides between load and GND.

What package type and thermal characteristics apply to the INA381A3IDGSR?

The INA381A3IDGSR uses the 10-pin VSSOP package (DGS) with 3.00 mm × 3.00 mm body size and exposed thermal pad. Its junction-to-ambient thermal resistance (R_θJA) is 188.6°C/W, and the thermal pad must be externally connected to GND for optimal thermal performance and electrical stability - as specified in the Thermal Information and Layout sections of the datasheet.