Texas Instruments INA381A2IDGSR

Overview

INA381A2IDGSR from Texas Instruments is a 26-V, high-speed current-sense amplifier with integrated comparator, configured for 50 V/V gain. It operates from 2.7 V to 5.5 V supply, supports –0.2 V to +26 V common-mode input range, delivers ≤1% gain error at 25°C, and achieves <10 µs total overcurrent protection response time in DC/DC power supplies and motor drives.

For engineers reviewing the INA381A2IDGSR datasheet, INA381A2IDGSR pinout, INA381A2IDGSR application, or INA381A2IDGSR equivalent, this page provides verified functional context, validated package mapping (VSSOP-10), confirmed pin roles, real-world timing behavior (400 ns comparator propagation delay), and accurate alternative part comparisons for overcurrent monitoring designs.

Technical Context

The INA381A2IDGSR implements a zero-drift topology enabling ≤150 µV max offset at 0 V common-mode and 1 µV/°C drift over –40°C to +125°C. Its internal architecture decouples common-mode voltage (–0.2 V to +26 V) from supply rail (2.7 V–5.5 V), supporting both high-side and low-side shunt sensing without damage during supply removal.

The device integrates a precision current-sense amplifier and an open-drain comparator with 50 mV hysteresis and configurable transparent/latched alert modes. Total system overcurrent response is <10 µs, combining amplifier bandwidth (210 kHz for A2 variant) and comparator propagation delay (400 ns typ).

Key Specifications

Pinout & Package

VSSOP-10 package (3.00 mm × 3.00 mm body), thermally enhanced with exposed thermal pad tied to GND. Pin numbering follows TI standard top-view orientation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA381A1IDGSR and INA381A3IDGSR, the INA381A2IDGSR offers optimal trade-off between sensitivity (20-mV full-scale), bandwidth (210 kHz), and noise immunity - making it the preferred choice for 10–100 A DC/DC and motor control applications requiring balanced performance.

Availability

INA381A2IDGSR is available at Aetrix Electronics and suitable for merchant server PSUs, DC-input BLDC motor drives, and cordless power tools requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for INA381A2IDGSR 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 signal chain and power management solutions.

The INA381 product line delivers integrated current-sense amplifiers with onboard comparators for real-time overcurrent protection in high-reliability power systems - designed specifically for server, industrial motor, and portable equipment markets.

FAQ

What is the maximum common-mode voltage the INA381A2IDGSR can handle?

The INA381A2IDGSR supports a common-mode input voltage range of –0.2 V to +26 V, independent of its 2.7–5.5 V supply voltage. This allows direct connection to 24-V bus rails while operating from a 3.3-V microcontroller supply. The device remains undamaged even if VS is removed while 26-V common-mode is present at IN+ and IN− pins.

Does the INA381A2IDGSR require external components to operate as a complete overcurrent detector?

The INA381A2IDGSR requires only two external components for basic overcurrent detection: a 10-kΩ pull-up resistor on the ALERT pin and a voltage divider or precision reference (e.g., REF3140) on CMPREF to set the trip threshold. No external op-amp, comparator, or filtering is needed - the integrated 50 V/V amplifier and comparator with 50 mV hysteresis provide full functionality in one VSSOP-10 package.

How does the RESET pin affect alert behavior in the INA381A2IDGSR?

The RESET pin on the INA381A2IDGSR configures the ALERT output mode: when pulled low, it enables latched mode (ALERT stays active until RESET is toggled high); when pulled high or left floating (with external pull-up), it enables transparent mode (ALERT follows CMPIN/CMPREF comparison in real time). This eliminates firmware polling or external latch circuits in safety-critical systems.

What is the typical total overcurrent response time of the INA381A2IDGSR?

The total system overcurrent response time of the INA381A2IDGSR is less than 10 µs - comprising amplifier settling, comparator propagation (400 ns typ), and output drive delay. This is measured from the moment the shunt voltage exceeds the programmed threshold to stable low state on the ALERT pin, verified across –40°C to +125°C and 2.7–5.5 V supply range.

Can the INA381A2IDGSR be used with a 12-V shunt sensing configuration?

Yes - the INA381A2IDGSR is explicitly rated for 26-V common-mode operation and is commonly deployed in 12-V high-side configurations (e.g., server 12-V VRMs). With its –0.2 V to +26 V input range and 50 V/V gain, it accurately amplifies 10–200 mV shunt drops into 0.5–10 V outputs compatible with 3.3-V or 5-V ADCs, while rejecting bus noise via 84–100 dB CMRR.