Texas Instruments INA303A1IPW

Overview

INA303A1IPW from Texas Instruments is a 36-V, precision current-sense amplifier with dual integrated comparators configured as a window comparator for simultaneous overcurrent and undercurrent detection. It delivers 20 V/V gain, ±30 µV max offset voltage, <1 µs ALERT1 response, and operates from 2.7–5.5 V supply while monitoring common-mode voltages from –0.1 V to +36 V - used in motor control overcurrent protection circuits with bidirectional shunt sensing.

For engineers reviewing the INA303A1IPW datasheet, INA303A1IPW pinout, INA303A1IPW application, or INA303A1IPW equivalent, key selection criteria include its window-comparator architecture, independent latch control per alert, adjustable ALERT2 delay (2 µs–10 s), TSSOP-14 package compatibility with high-density PCB layouts, and guaranteed performance across –40°C to +125°C.

Technical Context

The INA303A1IPW integrates a zero-drift, bidirectional current-sense amplifier with two dedicated comparators: COMP1 functions as a fast overlimit detector (<1 µs propagation), while COMP2 implements a programmable window threshold with external CDELAY-based timing (2 µs–10 s). Its REF pin enables bidirectional output swing centered on an externally set reference voltage.

Common-mode input range (–0.1 V to +36 V) is fully decoupled from the 2.7–5.5 V supply rail, enabling direct high-side sensing on 12 V, 24 V, or 36 V power rails without level-shifting. Each comparator uses a precision internal current source (80 µA typ) to convert external resistive limit settings into accurate voltage thresholds at LIMIT1 and LIMIT2 pins.

Key Specifications

Pinout & Package

Packaged in a 14-pin TSSOP (4.40 mm × 5.00 mm), the INA303A1IPW supports surface-mount assembly and thermal dissipation up to 110.2°C/W junction-to-ambient.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA302A1IPW and INA240A1PW, the INA303A1IPW uniquely provides factory-configured window-comparator functionality in a single IC - reducing component count, layout area, and qualification effort for applications requiring coordinated over/undercurrent validation without external logic.

Availability

INA303A1IPW is available at Aetrix Electronics and suitable for motor control, power-supply protection, and industrial PLC current-loop diagnostics requiring stable component supply and extended temperature support.

Supply support for INA303A1IPW 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 INA30x product line targets high-reliability current monitoring in industrial, automotive, and computing systems - delivering integrated amplification, comparison, and fault signaling in compact packages for space- and safety-critical designs.

FAQ

What is the maximum common-mode voltage the INA303A1IPW can measure?

The INA303A1IPW supports a common-mode input voltage range of –0.1 V to +36 V, independent of its 2.7–5.5 V supply voltage. This allows direct high-side sensing on 24 V or 36 V rails without level-shifting circuitry. The specification is guaranteed across the full –40°C to +125°C operating temperature range, and the device remains functional even if the common-mode voltage exceeds the absolute maximum rating of 40 V for brief transients, provided input current is limited to 5 mA per pin.

How does the window-comparator function work in the INA303A1IPW?

The INA303A1IPW implements a true window comparator: COMP1 triggers ALERT1 when the amplified shunt voltage exceeds the LIMIT1 threshold (overcurrent), and COMP2 triggers ALERT2 when it falls below the LIMIT2 threshold (undercurrent). LIMIT1 and LIMIT2 are set independently using external resistors that interface with internal 80 µA current sources. Unlike the INA302A1IPW, the INA303A1IPW's comparators are hardwired in window mode - no configuration register or pin strapping is required.

Can the INA303A1IPW operate with a 3.3 V supply and still sense 36 V common-mode signals?

Yes. The INA303A1IPW's amplifier and comparators are designed with a fully isolated input stage: the –0.1 V to +36 V common-mode range is electrically decoupled from the 2.7–5.5 V VS supply. When powered from 3.3 V, the device maintains full accuracy, <1 µs ALERT1 response, and valid operation across its entire temperature range. The only supply-dependent parameter is the output swing (VS – 0.1 V max high, GND + 30 mV min low), which remains compatible with 3.3 V logic interfaces.

What is the purpose of the DELAY pin on the INA303A1IPW?

Pin 10 (DELAY) controls the response timing of ALERT2 by charging an external capacitor (CDELAY). The internal 5 µA current source charges CDELAY until it reaches a 1.22 V threshold, at which point COMP2 triggers. Delay time is calculated as t ≈ CDELAY × 250 kΩ (e.g., 100 pF yields ~25 µs). This feature allows rejection of short-duration inrush currents while preserving sensitivity to sustained faults - critical in motor start-up or hot-swap applications where the INA303A1IPW is deployed.

Does the INA303A1IPW support bidirectional current sensing, and how is it implemented?

Yes. Bidirectional sensing is enabled by applying a reference voltage to the REF pin (pin 4). With REF biased at VS/2 (e.g., 1.65 V on 3.3 V supply), the OUT pin swings above REF for positive current (IN+ > IN–) and below REF for negative current (IN– > IN+). The amplifier's rail-to-rail output stage and zero-drift architecture ensure symmetrical accuracy in both directions - essential for regenerative braking monitoring or H-bridge current reconstruction using the INA303A1IPW.