Texas Instruments INA250A4PWR

Overview

INA250A4PWR from Texas Instruments is a bidirectional, precision current-sense amplifier with an integrated 2 mΩ shunt resistor, 2 V/A gain, ±15 A continuous current capability at –40°C to 85°C, and 108–118 dB CMRR over –40°C to 125°C - used for high-accuracy power rail monitoring in telecom power supplies.

For engineers reviewing the INA250A4PWR datasheet, INA250A4PWR pinout, INA250A4PWR application, or INA250A4PWR equivalent, key selection considerations include its Kelvin-connected internal shunt, 2 V/A output scaling for low-noise ADC interfacing, –0.1 V to 36 V common-mode range, and TSSOP-16 thermal performance (R_θJA = 104.4°C/W).

Technical Context

The INA250A4PWR implements a zero-drift, 36-V common-mode current-sense amplifier paired with a matched 2 mΩ Kelvin shunt, enabling system-calibrated accuracy without external calibration. Its bidirectional operation is controlled via the REF pin voltage, supporting both unidirectional (REF = GND) and bidirectional (REF = mid-supply) sensing modes.

It features a 11 dB higher CMRR than the INA250A3 version (108–118 dB vs. 106–114 dB), 27 nV/√Hz input-referred voltage noise, and 11 kHz bandwidth - optimized for stable, low-drift measurements in high-side or low-side configurations across wide temperature and supply ranges.

Key Specifications

Pinout & Package

Packaged in a 16-pin TSSOP (PW) measuring 5.00 mm × 6.40 mm, the INA250A4PWR uses a thermally enhanced layout with three dedicated GND pins (6, 8, 11) and Kelvin connections (SH+, SH–) for precision shunt sensing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA250A4PWR, INA240A4D offers higher CMRR but demands precise external shunt implementation, while MAX40056ATA+T provides integration at lower temperature rating and reduced current range - making INA250A4PWR the only option combining 125°C rating, 2 mΩ Kelvin shunt, and 2 V/A scaling in TSSOP-16.

Availability

INA250A4PWR is available at Aetrix Electronics and suitable for telecom power supplies, solar inverters, automotive battery management, and server power distribution units requiring stable component supply across extended temperature and high-reliability production cycles.

Supply support for INA250A4PWR 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 ICs.

The INA250 family was designed specifically for high-accuracy, integrated current sensing in power-constrained, thermally demanding applications - eliminating calibration and layout variability inherent in discrete shunt-amplifier solutions.

FAQ

What is the maximum continuous current rating for INA250A4PWR at 125°C ambient?

The INA250A4PWR supports ±10 A continuous current at 125°C ambient temperature, as specified in Figure 7-1 of the datasheet. This derating from ±15 A (at 85°C) ensures junction temperature remains below 150°C with standard 1-oz copper PCB layout and no forced airflow. The device's 4.5 mΩ total package resistance governs thermal limits, not silicon dissipation.

Can INA250A4PWR measure bidirectional current without external components?

Yes, INA250A4PWR supports true bidirectional current sensing using only an external reference voltage applied to the REF pin. Setting REF to VS/2 (e.g., 2.5 V with 5 V supply) centers the output at mid-scale, allowing positive current to increase OUT and negative current to decrease it - no external op-amps, level shifters, or dual-supply rails required.

What is the purpose of the SH+ and SH– pins on INA250A4PWR?

The SH+ and SH– pins provide Kelvin connections to the internal 2 mΩ shunt resistor. They must be wired separately from the high-current IN+ and IN– paths to eliminate voltage drop errors caused by PCB trace resistance. Connecting VIN+ to SH+ and VIN– to SH– ensures the amplifier measures only the true shunt voltage - critical for maintaining <0.1% gain accuracy.

How does the integrated shunt in INA250A4PWR differ from using a discrete shunt resistor?

The integrated shunt in INA250A4PWR is factory-matched to the amplifier's gain and temperature coefficients, achieving ≤±0.3% total system gain error - impossible with discrete solutions due to component tolerances and thermal gradients. Its Kelvin structure is permanently optimized, eliminating layout sensitivity and reducing PCB area by >70% versus discrete shunt + amplifier designs.

Is INA250A4PWR compatible with 3.3 V microcontrollers for direct ADC interfacing?

Yes, INA250A4PWR's 2 V/A gain produces a 0–20 V output at ±10 A, but its output swing is rail-to-rail within 50 mV of GND and 200 mV of VS. When powered from 5 V, it delivers 0.05–4.8 V output - fully compatible with 3.3 V ADCs using a simple resistive divider or buffer. No level-shifting circuitry is needed for most 12-bit+ MCUs.