Texas Instruments INA338AIDGST

Overview

INA338AIDGST from Texas Instruments is a high-temperature, precision instrumentation amplifier with shutdown control, designed for low-level sensor signal conditioning in single-supply systems. It delivers 100 µV max input offset voltage, 0.4 µV/°C max drift, and operates from –40°C to +125°C in MSOP-10 package. Its rail-to-rail input range (extending 0.25 V beyond V– and 0.1 V beyond V+) enables direct interface with bridges, load cells, and thermocouples.

For engineers reviewing the INA338AIDGST datasheet, INA338AIDGST pinout, INA338AIDGST application, or INA338AIDGST equivalent, this page provides verified technical context, validated pin functions, confirmed operating parameters across temperature, and real-world design implications for transducer amplification, medical instrumentation, and multi-channel data acquisition.

Technical Context

The INA338AIDGST employs a proprietary current-mode topology that converts differential input voltage into proportional current, eliminating dependence on resistor matching for common-mode rejection. This architecture achieves 100–120 dB CMR over DC–1 kHz and maintains stability without external trimming.

It integrates an internal auto-correction circuit operating at 90 kHz ±20% to suppress 1/f noise-especially effective at gains ≥100-and uses external R1/R2 resistors to set gain per G = 2(R₂/R₁), with supported range from <0.1 to >10,000 V/V. The Enable pin (Pin 6) controls power-down mode, reducing quiescent current from 2.4 mA to 2–5 µA.

Key Specifications

Pinout & Package

INA338AIDGST is housed in a 10-pin MSOP (DGS) package, 3.05 mm × 4.78 mm × 1.07 mm, JEDEC MO-187 compliant, with exposed thermal pad (not electrically connected). Pin 5 must be tied to V+ for proper operation; Pin 6 is the active-high Enable control.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA338AIDGST, INA326 offers smaller size and lower cost but forfeits shutdown capability and high-temp operation; INA128 delivers better initial accuracy and CMR but lacks integrated noise suppression and consumes less current only at low gains-making INA338AIDGST optimal for rugged, low-power, wide-dynamic-range transducer interfaces.

Availability

INA338AIDGST is available at Aetrix Electronics and suitable for weigh scales, automotive pressure sensors, and portable medical instrumentation requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for INA338AIDGST 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 signal chain solutions.

The INA338 belongs to TI's high-temperature instrumentation amplifier product line, engineered specifically for reliable, low-drift signal conditioning in harsh environments-from automotive under-hood systems to industrial process control.

FAQ

What is the required external resistor configuration for G = 100 on INA338AIDGST?

The INA338AIDGST achieves G = 100 using R1 = 2 kΩ and R2 = 100 kΩ, per the gain equation G = 2(R₂/R₁). R1 must be ≥2 kΩ to limit input stage current; R2 should be paired with C2 to set the desired filter corner frequency-e.g., 100 kΩ || 1 nF yields ~1.6 kHz pole. Layout best practices require minimizing stray capacitance on pins 1 and 8 to preserve high-frequency CMR.

How does the INA338AIDGST handle input bias current return paths?

The INA338AIDGST exhibits ±0.2 nA typical input bias current at 25°C, with minimal variation over temperature. A defined DC return path must be provided to both VIN+ and VIN–-typically via matched high-value resistors (e.g., 10 MΩ to V– or IACOMMON)-to prevent floating inputs and invalid output voltages. Without this path, the amplifier may saturate or produce unpredictable offsets.

Can the INA338AIDGST operate from a single 3.3 V supply?

Yes, the INA338AIDGST is fully specified from +2.7 V to +5.5 V, including 3.3 V operation. At 3.3 V, its input common-mode range extends from 0.25 V above V– to 0.1 V above V+, and output swings to within 0.25 V of V– and 0.075 V of V+. Quiescent current remains 2.4 mA (active) and drops to ≤5 µA in shutdown-making it viable for battery-powered 3.3 V systems.

Why must Pin 5 (IACOMMON) be connected to V+ on the INA338AIDGST?

Pin 5 on the INA338AIDGST is the reference terminal for the output stage and must be tied to V+ to ensure correct internal biasing of the shutdown circuitry and stable operation of the current-mode gain path. Leaving Pin 5 unconnected or grounding it will disable proper enable/disable functionality and may cause output instability or excessive offset. This differs from the INA337, where Pin 5 is freely configurable.

What is the impact of the 90 kHz auto-correction clock on system-level noise performance?

The 90 kHz internal oscillator in the INA338AIDGST generates spurious tones visible in the output spectrum near 90 kHz and its harmonics. These can alias into baseband if undersampled or interfere with adjacent RF circuits. To mitigate, TI recommends using a 1 kHz or lower output filter (RO/CO), which attenuates these components by >40 dB while preserving signal integrity for DC–100 Hz sensor applications.