Texas Instruments INA250A1PW

Overview

INA250A1PW from Texas Instruments is a bidirectional, precision current-sense amplifier with an integrated 2 mΩ shunt resistor, 200 mV/A gain, ±15 A continuous current capability at –40°C to 85°C, and 0.3% max system gain error - used in server power rails and telecom DC-DC monitoring for accurate real-time current feedback.

For engineers reviewing the INA250A1PW datasheet, INA250A1PW pinout, INA250A1PW application, or INA250A1PW equivalent, key selection criteria include its Kelvin-connected internal shunt, 36-V common-mode range (–0.1 V to 36 V), –40°C to 125°C operating temperature, TSSOP-16 package, and 50 kHz bandwidth with 51 nV/√Hz input-referred noise.

Technical Context

The INA250A1PW integrates a laser-trimmed 2 mΩ shunt resistor with a zero-drift, 36-V common-mode current-sense amplifier in a single TSSOP-16 package. Its Kelvin sensing architecture (SH+, SH–, VIN+, VIN–) eliminates parasitic PCB trace resistance errors, enabling high-accuracy bidirectional measurement independent of supply voltage.

It operates from 2.7 V to 36 V supply, draws ≤300 µA quiescent current, and delivers rail-to-rail output swing (to VS – 0.2 V and GND + 50 mV). The REF pin supports external biasing for bidirectional current detection, while CMRR exceeds 94 dB across –40°C to 125°C.

Key Specifications

Pinout & Package

Packaged in a 16-pin TSSOP (PW) measuring 5.00 mm × 6.40 mm, the INA250A1PW uses a thermally enhanced layout with three GND pins (6, 8, 11) and dedicated Kelvin sense terminals for optimal current-path integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA250A1PW, INA240A1PW offers extended common-mode range but lacks integrated shunt calibration, while MAX40056ATA+T provides faster response and higher voltage tolerance at the cost of reduced sensitivity - making INA250A1PW optimal for cost-sensitive, space-constrained 36-V systems requiring guaranteed 0.3% system accuracy.

Availability

INA250A1PW is available at Aetrix Electronics and suitable for server power monitoring, telecom DC-DC converters, and automotive battery management requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for INA250A1PW 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 INA250 family was designed specifically for high-accuracy, integrated-shunt current sensing in space-constrained power systems - targeting server, telecom, and automotive applications where board area, thermal stability, and system-level calibration burden must be minimized.

FAQ

What is the maximum continuous current rating for the INA250A1PW at 125°C ambient?

The INA250A1PW supports ±10 A continuous current at 125°C ambient temperature, as specified in Figure 7-1 of the datasheet. At lower temperatures (e.g., 85°C), it handles ±15 A continuously. Derating is required above 85°C due to package thermal resistance (RθJA = 104.4°C/W) and internal shunt self-heating. Proper PCB copper pour and airflow are critical to maintain this rating in actual designs.

Can the INA250A1PW measure bidirectional current, and how is it configured?

Yes, the INA250A1PW supports bidirectional current measurement via the REF pin. When REF is tied to GND, the device outputs 0 V at zero current and increases for positive current flow. For bidirectional operation, apply a mid-supply reference (e.g., 2.5 V) to REF - then positive current raises OUT above REF, and negative current lowers OUT below REF. This configuration is explicitly supported in the device functional modes section and requires no external components.

Does the integrated shunt resistor in the INA250A1PW support standalone use without the amplifier?

No - the integrated shunt resistor in the INA250A1PW is not intended for standalone use. As stated in the datasheet (Section 6.5 footnote 7), using it separately yields ~5% tolerance versus the specified 0.1%, because system calibration relies on matching between the shunt and amplifier. The device is characterized and tested only as an integrated unit; standalone use voids accuracy specifications and is not supported by Texas Instruments.

What is the output voltage swing capability of the INA250A1PW?

The INA250A1PW delivers rail-to-rail output swing: minimum output is GND + 25 mV (typical) and maximum is VS – 0.1 V (typical) at RL = 10 kΩ to GND. Under load, output impedance is 1.5 Ω, so heavier loads reduce swing margin. For example, at 1 mA load, the drop is ~1.5 mV - negligible for most ADC interfaces. Full swing is maintained across –40°C to 125°C, as verified in Figure 6-19.

How does the INA250A1PW achieve high common-mode rejection across temperature?

The INA250A1PW achieves ≥94 dB CMRR from –40°C to 125°C through its zero-drift amplifier architecture and matched internal resistor network. Unlike chopper-stabilized amplifiers, it uses auto-zeroing with low-frequency correction, minimizing drift-induced CMR degradation. The integrated 2 mΩ shunt's tight tempco (10 ppm/°C) prevents thermal gradient errors that degrade CMRR in discrete shunt solutions - ensuring stable rejection even under thermal stress.