Texas Instruments INA114AU/1KG4

Overview

INA114AU/1KG4 from Texas Instruments is a precision instrumentation amplifier designed for high-accuracy signal conditioning in noisy industrial and medical environments. It delivers 50 µV max offset voltage, 0.3 µV/°C max drift, 115 dB min CMRR at G = 1000, ±2.25 V to ±18 V dual-supply operation, and ±40 V input over-voltage protection - enabling reliable bridge sensor readout in surgical equipment and train control systems.

For engineers reviewing the INA114AU/1KG4 datasheet, INA114AU/1KG4 pinout, INA114AU/1KG4 application, or INA114AU/1KG4 equivalent, key selection criteria include guaranteed low-drift performance across –40°C to +85°C, single-resistor programmable gain (1–10,000), SOIC-16 package compatibility with remote output sensing, and input protection that survives ±40 V common-mode overload without damage.

Technical Context

The INA114AU/1KG4 implements a three-op-amp architecture with laser-trimmed internal resistors, enabling precise gain setting via a single external resistor (RG) and delivering stable performance across chip site origins SHE and TID. Its input stage features FET-based amplifiers with 100 GΩ || 6 pF common-mode and differential impedance, supporting high-impedance transducer interfaces while maintaining >110 dB CMRR up to 60 Hz.

Internal input protection circuitry clamps current to ~1.5 mA during ±40 V overvoltage events, operating independently of supply presence. The SOIC-16 variant includes dedicated output sense (pin 12) for remote load feedback, while the PDIP-8 version integrates this path internally - a functional distinction critical for closed-loop accuracy in precision current/voltage converters.

Key Specifications

Pinout & Package

INA114AU/1KG4 is supplied in a 16-pin SOIC (DW) surface-mount package (10.3 mm × 10.3 mm), optimized for automated assembly and thermal management (R_θJA = 74.2 °C/W). Pin 12 provides dedicated output sense feedback, requiring external connection to pin 11 for accurate remote-load regulation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA114AU/1KG4, INA128UA/2K5 offers superior DC precision but sacrifices ruggedness, while AD8421ARMZ delivers speed and noise performance at the cost of design complexity and external protection overhead - making INA114AU/1KG4 the optimal balance of accuracy, robustness, and integration for transportation and medical OEMs.

Availability

INA114AU/1KG4 is available at Aetrix Electronics and suitable for surgical equipment, train control and management, and trackside signaling and control requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for INA114AU/1KG4 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 heritage in precision amplifier design and automotive-grade reliability validation.

The INA114 product line targets cost-sensitive, high-reliability industrial and medical instrumentation - delivering laser-trimmed accuracy and integrated protection in industry-standard packages for rapid system integration.

FAQ

What is the maximum gain achievable with INA114AU/1KG4, and how is it set?

The INA114AU/1KG4 supports gains from 1 to 10,000 V/V, set by a single external resistor RG connected between pins 1 and 8. The gain equation is G = 1 + 50 kΩ/RG. For G = 10,000, RG = 5 Ω - requiring careful layout to minimize parasitic resistance. At high gains, wiring and socket resistance directly impact accuracy, so surface-mount RG placement adjacent to pins 1/8 is recommended for INA114AU/1KG4 designs.

Does INA114AU/1KG4 require external input protection when used in industrial environments?

No, INA114AU/1KG4 does not require external input protection for ±40 V common-mode or differential overvoltage conditions. Its internal protection circuitry limits input current to ~1.5 mA during overload, preventing damage even with no supply applied. This capability is confirmed in the Absolute Maximum Ratings table and validated across all chip site origins (SHE and TID), making INA114AU/1KG4 suitable for direct connection to field wiring in train control cabinets without added TVS diodes.

How does the SOIC-16 package of INA114AU/1KG4 differ functionally from the PDIP-8 version?

The INA114AU/1KG4 SOIC-16 package includes dedicated output sense pins (pin 11 for OUT SENSE, pin 12 for SENSE) that must be externally connected to implement Kelvin-sense feedback. This feature is absent in the PDIP-8 variant, where the sense path is internal. For applications demanding <0.1% load regulation accuracy - such as precision 4–20 mA transmitters driving long cables - the SOIC-16's separate sense terminals are essential, whereas PDIP-8 suffices for local PCB-mounted loads.

What is the guaranteed common-mode rejection ratio (CMRR) for INA114AU/1KG4 at G = 1000?

The INA114AU/1KG4 guarantees a minimum CMRR of 106 dB at G = 1000, measured at DC to 60 Hz with VCM = ±10 V and ΔRS = 1 kΩ. This value applies specifically to the AU grade (as specified in Electrical Characteristics Table 5.5) and ensures rejection of >99.9999% of 50/60 Hz interference - critical for ECG amplifiers and trackside signaling receivers where mains noise dominates the signal band.

Can INA114AU/1KG4 operate from a single 5 V supply, and what are the output swing limitations?

Yes, INA114AU/1KG4 supports single-supply operation down to +4.5 V (per Recommended Operating Conditions), with output swing limited to (V–) +1 V to (V+) –1 V at ±2.25 V supplies - translating to 1 V to 4 V on a 5 V rail. This 3 V output range accommodates most 12-bit ADCs with 0–5 V input spans. Quiescent current remains stable (±2.2 to ±3 mA) across the full supply range, ensuring predictable power budgeting in battery-powered surgical tools using INA114AU/1KG4.