Texas Instruments INA2128UA

Overview

INA2128UA from Texas Instruments is a dual, low-power instrumentation amplifier designed for precision DC-coupled signal conditioning in sensor front-ends. It delivers 50 µV max offset voltage, 0.5 µV/°C max drift, 120 dB min CMR at G ≥ 100, and operates from ±2.25 V to ±18 V supplies with 700 µA per channel quiescent current-enabling high-accuracy measurements in battery-powered industrial transmitters.

For engineers reviewing the INA2128UA datasheet, INA2128UA pinout, INA2128UA application, or INA2128UA equivalent, key selection criteria include guaranteed low-drift performance across –40°C to +85°C, ±40 V input protection, single-resistor programmable gain (1–10,000), and SOIC-16 package compatibility with space-constrained analog input modules and medical ECG systems.

Technical Context

The INA2128UA employs a three-op-amp architecture with current-feedback input stages to maintain 1.3 MHz bandwidth at G = 1 while achieving 200 kHz at G = 100. Its laser-trimmed thin-film resistors ensure stable gain accuracy and low temperature drift without external trimming.

Input protection circuitry clamps transient overvoltages up to ±40 V independently on each input, surviving even with power supplies disconnected. The dual-channel design features fully isolated bias networks and < –120 dB crosstalk at 1 kHz, enabling simultaneous high-precision measurement of two independent sensor signals without mutual interference.

Key Specifications

Pinout & Package

INA2128UA is housed in a 16-pin SOIC (DW) package measuring 10.3 mm × 10.3 mm, with standard 1.27 mm pitch and JEDEC MS-012 compliant footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA2128U and AD8428ARZ, the INA2128UA provides the optimal balance of dual-channel flexibility, programmable gain, ±40 V input ruggedness, and 1.4 mA total supply current-making it uniquely suitable for cost-sensitive, space-constrained, and field-deployed analog input modules requiring long-term stability without recalibration.

Availability

INA2128UA is available at Aetrix Electronics and suitable for pressure transmitter, temperature transmitter, and weigh scale applications requiring stable component supply across multi-year production cycles.

Supply support for INA2128UA 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 expertise in precision signal chain solutions.

The INA2128 product line was engineered specifically for high-accuracy, low-power industrial sensor signal conditioning-targeting applications where long-term drift, input protection, and dual-channel integration are critical design requirements.

FAQ

What is the maximum gain achievable with INA2128UA?

The INA2128UA supports gain settings from 1 V/V to 10,000 V/V using a single external resistor (RG) connected between pins 6 and 14. At G = 10,000, the required RG is 5 Ω; layout parasitics and trace resistance become significant above G = 100, so precision metal-film resistors and Kelvin connections are recommended. The INA2128UA maintains 110 dB CMR even at G = 1000, ensuring signal integrity across its full gain range.

Does INA2128UA require external offset nulling components?

No, the INA2128UA does not require external offset nulling components. It is laser-trimmed at wafer level to achieve ≤50 µV offset voltage and ≤0.5 µV/°C drift across –40°C to +85°C, eliminating the need for potentiometers or digital calibration in most industrial applications. An optional external op-amp buffer can be added to the REF pin only if system-level offset adjustment beyond factory trim is required-for example, in field-serviceable medical devices where end-user calibration is mandated.

Can INA2128UA operate from a single 5-V supply?

Yes, the INA2128UA supports single-supply operation from 4.5 V to 36 V, including 5 V. When powered from 5 V, the input common-mode range is limited to approximately 2 V to 3 V (V– + 2 V to V+ – 2 V), and output swing reaches within 1.4 V of each rail. For optimal performance at low supply, use the REF pins to level-shift the output baseline and ensure input signals remain within the linear operating region-verified in Figure 5-10 of the INA2128UA datasheet.

How does INA2128UA handle input overvoltage conditions?

The INA2128UA incorporates internal input protection circuitry that safely clamps voltages up to ±40 V on either input terminal-even with power supplies disconnected. During overload, current is limited to 1.5–5 mA, preventing damage to internal ESD structures. This eliminates the need for external series resistors or TVS diodes in industrial I/O modules, while preserving low input bias current (≤5 nA) and high impedance (10¹⁰ Ω) under normal operation-critical for high-impedance sensor interfaces.

What is the channel-to-channel crosstalk specification for INA2128UA?

The INA2128UA exhibits < –120 dB typical crosstalk at 1 kHz, as confirmed by Figure 5-11 in the official datasheet. This near-isolation results from physically separate input bias networks, independent reference paths, and dedicated output sense terminals for each channel. In PCB layout, maintaining >3 mm spacing between Channel A and Channel B input traces-and routing differential pairs adjacently-ensures crosstalk remains below –110 dB up to 100 kHz, making the INA2128UA suitable for simultaneous dual-sensor acquisition in analog input modules.