Texas Instruments INA2128U/1KG4

Overview

INA2128U/1KG4 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, 1.3 MHz bandwidth at G=1, 120 dB min CMR, and ±40 V input protection-enabling high-accuracy measurement in pressure transmitters and ECG systems.

For engineers reviewing the INA2128U/1KG4 datasheet, INA2128U/1KG4 pinout, INA2128U/1KG4 application, or INA2128U/1KG4 equivalent, key selection criteria include dual-channel matched performance, laser-trimmed DC accuracy, current-feedback architecture for stable high-gain bandwidth, and SOIC-16 packaging compatible with industrial PCB layouts.

Technical Context

The INA2128U/1KG4 employs a three-op-amp current-feedback topology that maintains 200 kHz bandwidth even at G = 100, enabling fast settling (7 µs to 0.01% at G=1) without sacrificing DC precision. Its laser-trimmed internal resistors ensure gain accuracy of ±0.01% at G=1 and ±0.025% at G=100, while independent bias networks per channel minimize inter-channel crosstalk.

Input protection circuitry withstands ±40 V continuously-even with supplies off-by limiting input current to 1.5–5 mA. The device operates from ±2.25 V to ±18 V dual supply or 4.5 V to 36 V single supply, supporting battery-powered and wide-range industrial systems.

Key Specifications

Pinout & Package

INA2128U/1KG4 is housed in a 16-pin SOIC (DW) package measuring 10.3 mm × 10.3 mm, with standard 1.27 mm pitch and exposed pad not present. Pin functions are validated per TI SBOS035C Figure 4-1 (top view).

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA2128U/1KG4, the INA2129U/1K improves DC precision at the cost of power efficiency, while the AD8428ARZ trades configurability and robustness for raw speed and noise performance-making INA2128U/1KG4 the optimal balance for general-purpose dual-channel industrial sensing.

Availability

INA2128U/1KG4 is available at Aetrix Electronics and suitable for pressure transmitter design, temperature transmitter calibration, and electrocardiogram (ECG) signal conditioning requiring stable component supply across long-lifecycle industrial and medical programs.

Supply support for INA2128U/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 expertise in precision signal chain solutions.

The INA2128U/1KG4 belongs to TI's high-accuracy instrumentation amplifier product line, engineered specifically for low-drift, low-noise DC signal conditioning in industrial sensor interfaces and medical instrumentation.

FAQ

What is the maximum gain achievable with INA2128U/1KG4?

The INA2128U/1KG4 supports gains from 1 V/V to 10,000 V/V using a single external resistor (RG) per channel, calculated as G = 1 + (50 kΩ / RG). At G = 10,000, RG = 5 Ω; however, practical implementation requires careful attention to parasitic resistance and thermal EMF effects. The device maintains 20 kHz bandwidth and ±0.5% gain nonlinearity at this setting, as verified in TI SBOS035C Section 5.5.

Does INA2128U/1KG4 require external offset trimming?

No-INA2128U/1KG4 is laser-trimmed at wafer level to achieve ≤50 µV offset voltage and ≤0.5 µV/°C drift, eliminating the need for external trimming in most applications. Section 6.2.4 of the TI datasheet confirms that typical systems operate within specification without adjustment. An optional trim circuit using the Ref pin is provided only for applications demanding sub-10 µV residual offset.

Can INA2128U/1KG4 operate from a single 5-V supply?

Yes-INA2128U/1KG4 supports single-supply operation from 4.5 V to 36 V, as specified in Section 5.3 of the datasheet. At 5 V, the input common-mode range is limited to approximately (V–) + 2 V to (V+) – 2 V, and output swing reduces to ~0.4 V to 4.6 V. Performance remains fully characterized, including 120 dB CMR at G ≥ 100 and 700 µA per channel quiescent current.

How does INA2128U/1KG4 handle input overvoltage conditions?

INA2128U/1KG4 features integrated input protection that withstands continuous ±40 V applied to either input-even with supplies disconnected. Internal circuitry limits input current to 1.5–5 mA during overload, preventing damage while maintaining functionality. This is validated per Absolute Maximum Ratings (Section 5.1) and illustrated in Figures 5-17 and 5-18 of the SBOS035C datasheet.

Is INA2128U/1KG4 pin-compatible with other TI dual instrumentation amplifiers?

No-INA2128U/1KG4 uses a proprietary 16-pin SOIC pinout optimized for dual-channel independence, including separate Sense, Ref, and gain-set terminals per channel. It is not pin-compatible with INA2126, INA2129, or INA128. Layout reuse requires verification against TI SBOS035C Figure 4-1; migration to alternate parts necessitates schematic and PCB revision.