Texas Instruments INA381A2IDSGR

Overview

INA381A2IDSGR 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 BLDC motor drives.

For engineers reviewing the INA381A2IDSGR datasheet, INA381A2IDSGR pinout, INA381A2IDSGR application, or INA381A2IDSGR equivalent, this page provides verified pin functions, real-world timing performance (400 ns comparator propagation delay), confirmed package mapping (WSON-8), and two validated alternative parts with documented functional and application differences.

Technical Context

The INA381A2IDSGR 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 sensing without damage during supply removal.

It integrates a precision amplifier (50 V/V fixed gain, 210 kHz bandwidth, 2 V/µs slew rate) and an open-drain comparator with 50 mV hysteresis, 400 ns typical propagation delay, and user-selectable transparent/latched alert modes via the RESET pin.

Key Specifications

Pinout & Package

INA381A2IDSGR is housed in an 8-pin WSON package (2.00 mm × 2.00 mm, 0.5-mm pitch) with exposed thermal pad tied to GND. The package supports reflow soldering per JEDEC J-STD-020 and provides 43.4°C/W junction-to-board thermal resistance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA381A1IDSGR and INA381A3IDSGR, the INA381A2IDSGR provides optimal gain for 0.2–1.0 A measurement ranges with 20–50 mΩ shunts, balancing noise immunity, dynamic range, and PCB area - making it the default choice for mid-power DC/DC and motor control designs.

Availability

INA381A2IDSGR is available at Aetrix Electronics and suitable for merchant DC/DC power supplies, DC-input BLDC motor drives, and cordless power tools requiring stable component supply across automotive-grade temperature ranges and long production lifecycles.

Supply support for INA381A2IDSGR 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 on-chip comparators for real-time overcurrent protection in high-reliability power conversion and motor control systems.

FAQ

What is the maximum common-mode voltage the INA381A2IDSGR can handle?

The INA381A2IDSGR 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 connection to 24-V bus rails even when powered from a 3.3-V microcontroller supply. The device remains undamaged if the full 26-V common-mode voltage is applied while the supply is removed, as confirmed in Section 6.1 Absolute Maximum Ratings of the SBOS848B datasheet.

Does the INA381A2IDSGR require external components for basic overcurrent detection?

Yes - the INA381A2IDSGR requires an external 10-kΩ pullup resistor on the ALERT pin and a reference voltage source (e.g., resistive divider or REF3140) on CMPREF to set the overcurrent threshold. VOUT is typically connected directly to CMPIN. No external compensation or filtering is needed for stable operation, as the amplifier is unity-gain stable and the comparator includes built-in 50 mV hysteresis.

What is the total overcurrent response time of the INA381A2IDSGR?

The total system overcurrent protection response time of the INA381A2IDSGR is less than 10 µs, combining amplifier settling and comparator propagation. This includes <2 µs large-signal comparator response and amplifier contribution, as specified in the Description section (page 1) and validated in Figure 34 (VSENSE Voltage Response) of the SBOS848B datasheet. This timing enables protection in fast-switching motor drives and high-frequency DC/DC converters.

Can the INA381A2IDSGR be used for bidirectional current sensing?

No - the INA381A2IDSGR is designed for unidirectional current sensing only. Its input structure (IN+ referenced to higher potential, IN– to lower) and single-supply operation (2.7 V–5.5 V) do not support negative differential inputs below GND. For bidirectional applications, TI recommends the INA240 or INA199 families, which feature symmetric input ranges and dual-supply capability.

What package and thermal characteristics does the INA381A2IDSGR have?

The INA381A2IDSGR uses the 8-pin WSON package (DSG) with 2.00 mm × 2.00 mm body size and exposed thermal pad. Its junction-to-board thermal resistance is 43.4°C/W, and it supports reflow soldering per JEDEC J-STD-020. The thermal pad must be soldered to a solid GND plane to achieve rated performance and reliability, as detailed in Section 10 Layout and Table 6.4 Thermal Information of SBOS848B.