Texas Instruments INA2128UA/1KG4

Overview

INA2128UA/1KG4 from Texas Instruments is a dual, low-power instrumentation amplifier designed for precision 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 battery-powered industrial transmitters and medical ECG systems.

For engineers reviewing the INA2128UA/1KG4 datasheet, INA2128UA/1KG4 pinout, INA2128UA/1KG4 application, or INA2128UA/1KG4 equivalent, key selection considerations include dual-channel matched performance, laser-trimmed DC accuracy, current-feedback architecture for stable high-gain bandwidth, and SOIC-16 package compatibility with analog input modules requiring space-constrained, low-quiescent-current signal chains.

Technical Context

The INA2128UA/1KG4 implements a three-op-amp instrumentation amplifier topology with current-feedback input stages, enabling 200 kHz bandwidth even at G = 100. Its gain is set by a single external resistor (RG), supporting 1–10,000 V/V range via the equation G = 1 + (50 kΩ / RG).

Laser trimming ensures tight matching across both channels: 50 µV max input offset voltage, 0.5 µV/°C max drift, and ≥110 dB CMR at G ≥ 100. Input protection circuitry withstands ±40 V differential input without damage, and operation is supported from ±2.25 V to ±18 V dual supplies or 4.5 V to 36 V single supply.

Key Specifications

Pinout & Package

The INA2128UA/1KG4 is housed in a 16-pin SOIC (DW) package measuring 10.3 mm × 10.3 mm, optimized for automated assembly and thermal performance in compact PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA2128UA/1KG4, the INA2129UA/1KG4 offers superior CMR and bias current for demanding medical or metrology use, while the AD8226ARZ provides a lower-cost, single-channel alternative lacking input protection and dual-channel correlation - making INA2128UA/1KG4 optimal for dual-sensor industrial transmitters requiring robustness and matched performance.

Availability

INA2128UA/1KG4 is available at Aetrix Electronics and suitable for pressure transmitter, temperature transmitter, and electrocardiogram (ECG) systems requiring stable component supply, long-term production continuity, and guaranteed traceable sourcing.

Supply support for INA2128UA/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 amplifiers and sensor interface solutions.

The INA2128 product line was engineered for high-accuracy, low-power industrial and medical signal conditioning - emphasizing laser-trimmed DC performance, dual-channel correlation, and rugged input protection in compact SOIC packaging.

FAQ

What is the maximum gain achievable with the INA2128UA/1KG4?

The INA2128UA/1KG4 supports gains from 1 V/V to 10,000 V/V using a single external resistor (RG) configured per the equation G = 1 + (50 kΩ / RG). At G = 10,000, RG = 5 Ω, and bandwidth reduces to 20–33 kHz depending on chip site origin (CSO). The INA2128UA/1KG4 maintains functional stability up to this gain limit with appropriate PCB layout and decoupling.

Does the INA2128UA/1KG4 require external input protection components?

No. The INA2128UA/1KG4 integrates robust input protection that withstands ±40 V differential input voltage without damage - even with supplies disconnected. This eliminates the need for external clamping diodes or series resistors in most industrial and medical applications, reducing BOM count and board area. The INA2128UA/1KG4's internal protection limits input current to 1.5–5 mA during overload.

How does the INA2128UA/1KG4 handle crosstalk between its two channels?

The INA2128UA/1KG4 features fully independent channel circuitry - including separate bias networks and input stages - resulting in negligible DC crosstalk. At 100 kHz, typical crosstalk is <–100 dB. Layout best practices (e.g., grounded guard traces, separated input routing) further minimize capacitive coupling. The INA2128UA/1KG4's dual-channel isolation makes it suitable for simultaneous multi-lead ECG or dual-sensor bridge measurements.

What is the operating temperature range specified for the INA2128UA/1KG4?

The INA2128UA/1KG4 is specified for operation from –40°C to +85°C ambient temperature. All key parameters - including offset voltage (±50 µV max), drift (0.5 µV/°C max), CMR (≥110 dB at G ≥ 100), and quiescent current (700 µA per channel) - are guaranteed across this full industrial temperature range. The INA2128UA/1KG4's laser-trimmed design ensures consistent performance without recalibration.

Can the INA2128UA/1KG4 operate from a single supply?

Yes. The INA2128UA/1KG4 supports single-supply operation from 4.5 V to 36 V, in addition to dual-supply operation from ±2.25 V to ±18 V. When using single supply, the reference (RefA/RefB) pins must be biased to mid-rail (e.g., VS/2) to maintain linear input common-mode range. Output swing remains rail-to-rail compatible within the specified load conditions, and the INA2128UA/1KG4 retains all key specifications including 1.3 MHz bandwidth at G = 1.