Texas Instruments INA141U

Overview

INA141U from Texas Instruments is a precision instrumentation amplifier with fixed gain options of G = 10 or G = 100, low offset voltage (50 µV max), high CMR (117 dB min at G = 100), and SO-8 surface-mount package. It operates from ±2.25 V to ±18 V supplies, draws only 750 µA quiescent current, and is used in bridge, thermocouple, and RTD sensor signal conditioning where accuracy and input protection to ±40 V are required.

For engineers reviewing the INA141U datasheet, INA141U pinout, INA141U application, or INA141U equivalent, key selection considerations include its laser-trimmed gain accuracy (±0.05% at G = 10), input bias current (5 nA max), bandwidth (200 kHz at G = 100), and compatibility with low-voltage, battery-powered systems requiring stable DC performance and high common-mode rejection.

Technical Context

The INA141U employs a 3-op-amp current-feedback architecture that enables wide bandwidth even at high gain-200 kHz at G = 100-while maintaining low power consumption. Its internal laser-trimmed resistor network sets precise gains of 10 or 100 without external components, and over-voltage protection circuitry on both inputs withstands ±40 V continuously.

Input common-mode range extends to (V+) – 1.4 V and (V–) + 1.7 V at ±15 V supplies, narrowing at lower voltages; output swing is rail-to-rail limited by internal node headroom. The Ref pin establishes output reference potential and must be connected with low impedance to preserve CMR-8 Ω series resistance degrades typical CMR to ~80 dB.

Key Specifications

Pinout & Package

INA141U is housed in an 8-pin SOIC (SO-8) package per JEDEC MS-012, with 1.27 mm pitch and RoHS-compliant CU NIPDAU finish (MSL Level-3, 260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar instrumentation amplifier applications.

Compared with INA128UA and AD620ARZ, the INA141U uniquely combines fixed high-accuracy gain, ultra-low quiescent current, and integrated ±40 V input protection-making it optimal for unattended, battery-operated sensor nodes where reliability and calibration simplicity are prioritized over gain flexibility.

Availability

INA141U is available at Aetrix Electronics and suitable for bridge amplifier circuits, thermocouple signal conditioning, and RTD-based temperature sensing requiring stable component supply, long-term parametric consistency, and industrial-grade input fault tolerance.

Supply support for INA141U 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 headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The INA141U belongs to TI's precision instrumentation amplifier product line, engineered specifically for high-accuracy, low-power sensor signal conditioning in harsh environments-emphasizing laser-trimmed DC performance, input ruggedness, and ease of use in compact layouts.

FAQ

What gain options does the INA141U support, and how are they configured?

The INA141U supports two fixed gains: G = 10 (default, no connection between Pins 1 and 8) and G = 100 (jumper or 0 Ω resistor between Pins 1 and 8). Internal laser-trimmed resistors ensure ±0.05% gain accuracy at G = 10. External resistors are not supported-the INA141U is not designed for user-programmable gain. This configuration applies directly to the INA141U and is validated in the official TI datasheet SBOS052.

Does the INA141U require external input protection when used with ±40 V field signals?

No, the INA141U does not require external input protection for ±40 V signals-the device integrates robust input protection circuitry on both VIN+ and VIN– pins that safely clamp and limit current under overload conditions. This protection remains active even when power supplies are disconnected. The INA141U specification explicitly guarantees ±40 V fault tolerance, making it suitable for direct connection to industrial sensors without added diodes or resistors.

What is the maximum operating temperature range for the INA141U, and is it specified over this range?

The INA141U is specified for operation from –40°C to +85°C and functions reliably up to +125°C. All key parameters-including offset voltage, CMR, and gain error-are guaranteed over the –40°C to +85°C range per the datasheet. Junction temperature must not exceed +150°C. Thermal performance data (e.g., quiescent current vs. temperature) is provided across –75°C to +125°C, confirming stable behavior beyond the specified range-critical for the INA141U in sealed enclosures or high-ambient environments.

Can the INA141U operate from a single +5 V supply, and what design considerations apply?

Yes, the INA141U can operate from a single +5 V supply when biased appropriately-for example, by setting Ref to +2.5 V and ensuring VIN+ and VIN– remain within the input common-mode range (typically +0.8 V to +4.2 V at VS = +5 V). Output swing will be limited to ~0.9 V above V– and ~0.9 V below V+, so full-scale output must be centered accordingly. The INA141U's ±2.25 V minimum supply rating confirms viability in single-supply configurations, but input/output headroom constraints must be verified using the "Input Common-Mode Range vs Output Voltage" curves in the INA141U datasheet.

How does the Ref pin affect common-mode rejection in the INA141U, and what is the recommended connection?

The Ref pin defines the output reference potential and critically impacts CMR: a series resistance >1 Ω degrades typical CMR from 117 dB to ~80 dB at G = 1. It must be connected to a low-impedance node-ideally ground or a precision voltage reference buffer. If level-shifting is required, use an op-amp follower (e.g., OPA177) with < 0.1 Ω output impedance. This requirement is intrinsic to the INA141U's 3-op-amp topology and is explicitly documented in the INA141U application information section on "Setting the Reference."