Texas Instruments INA303A2IPW

Overview

INA303A2IPW from Texas Instruments is a 36-V bidirectional current-sense amplifier with integrated window comparator, configured for overcurrent and undercurrent detection in high-side or low-side shunt monitoring. It delivers 50 V/V gain, ≤30 µV max offset voltage (A2 version), 1 µs alert response on ALERT1, and adjustable 2 µs–10 s delay on ALERT2 - enabling precise fault detection in motor drives and server power rails.

For engineers reviewing the INA303A2IPW datasheet, INA303A2IPW pinout, INA303A2IPW application, or INA303A2IPW equivalent, this page provides verified functional identity, TSSOP-14 pin mapping, window-comparator timing behavior, precision sensing specs across –40°C to +125°C, and two validated alternative parts for overcurrent/undercurrent protection designs.

Technical Context

The INA303A2IPW implements a zero-drift chopper-stabilized amplifier core with 50 V/V fixed gain and ±50 mV input range (A2 variant), supporting bidirectional sensing via REF pin biasing. Its dual comparators operate in window mode: COMP1 triggers on overlimit (e.g., I > I_MAX), COMP2 on underlimit (e.g., I < I_MIN), each with independent threshold setting via external resistors at LIMIT1/LIMIT2 pins.

Alert timing is asymmetric: ALERT1 asserts within 1 µs of threshold breach; ALERT2 response is programmable via C_DELAY capacitor (2 µs–10 s), with internal 5 µA DELAY pin current and 1.22 V threshold. Both open-drain outputs support latched or transparent operation controlled by LATCH1/LATCH2 digital inputs.

Key Specifications

Pinout & Package

INA303A2IPW is housed in a 14-pin TSSOP package (4.4 mm × 5.0 mm, 0.65 mm pitch), optimized for thermal performance (R_θJA = 110.2°C/W) and PCB space efficiency in high-density power systems.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA302A2IPW, INA303A2IPW adds undercurrent detection capability essential for open-load safety checks; compared with INA240A2IPW, it integrates window-comparator logic to reduce system-level component count and improve fault-response determinism.

Availability

INA303A2IPW is available at Aetrix Electronics and suitable for motor control, server power rail monitoring, and industrial PLC output modules requiring stable component supply and guaranteed long-term availability.

Supply support for INA303A2IPW 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 amplifiers and power management ICs.

The INA30x family was designed specifically for high-accuracy, high-voltage current sensing with integrated fault detection - targeting applications where space-constrained, reliable overcurrent/undercurrent protection is critical.

FAQ

What is the key functional distinction between INA303A2IPW and INA302A2IPW?

The INA303A2IPW implements a window comparator configuration: ALERT1 signals overcurrent (I > I_MAX) and ALERT2 signals undercurrent (I < I_MIN). In contrast, the INA302A2IPW configures both comparators for overcurrent detection only. This makes INA303A2IPW uniquely suited for applications requiring open-load or no-load fault detection - such as motor phase loss or broken wiring - which the INA302A2IPW cannot provide.

How is the ALERT2 delay time calculated for INA303A2IPW?

The ALERT2 delay time for INA303A2IPW is determined by the external capacitor C_DELAY connected to the DELAY pin, using the formula t_DELAY = C_DELAY × 1.22 V / 5 µA. With the internal DELAY pin current fixed at 5 µA and threshold voltage at 1.22 V, a 10 pF capacitor yields ~2.4 µs delay, while a 100 nF capacitor achieves ~24 ms - covering the full 2 µs to 10 s specification range. The INA303A2IPW datasheet provides exact calculation guidance in Section 8.2.

Can INA303A2IPW perform bidirectional current sensing, and how is it implemented?

Yes, INA303A2IPW supports true bidirectional current sensing via its REF pin. Applying a mid-supply voltage (e.g., 2.5 V with 5 V VS) to REF centers the output: positive differential input (IN+ > IN−) produces V_OUT > V_REF, while negative differential input (IN+ < IN−) produces V_OUT < V_REF. This enables detection of current flow direction - critical for regenerative braking in motor drives or charge/discharge monitoring in battery systems - without external op-amps or level shifters.

What is the maximum common-mode voltage the INA303A2IPW can tolerate on its IN+ and IN− pins?

The INA303A2IPW accepts a common-mode input voltage range of –0.1 V to +36 V on its IN+ and IN− pins, independent of its 2.7–5.5 V supply voltage (VS). This allows direct connection to high-voltage power rails - such as 24 V industrial buses or 36 V automotive systems - while operating from a low-voltage microcontroller supply. The device maintains specified accuracy and functionality across this full range, with ≥110 dB CMRR (A2 version) rejecting rail noise.

Does INA303A2IPW require external components for basic operation, and which ones are mandatory?

Yes, INA303A2IPW requires three mandatory external components for functional operation: (1) a 0.1 µF bypass capacitor between VS and GND, (2) a pullup resistor (typically 10 kΩ) on each ALERT1 and ALERT2 output to a logic-compatible voltage, and (3) external resistors setting LIMIT1 and LIMIT2 thresholds (or DACs/voltage sources). The DELAY capacitor is optional unless programmable ALERT2 timing is needed. No external gain-setting components are required - gain is fixed at 50 V/V for the A2 variant.