Texas Instruments INA2128P

Overview

INA2128P 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 CMRR 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 pressure transmitters and ECG systems.

For engineers reviewing the INA2128P datasheet, INA2128P pinout, INA2128P application, or INA2128P 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 industrial DAQ systems.

Technical Context

The INA2128P uses a three-op-amp architecture with current-feedback input stages, enabling 1.3 MHz bandwidth at G = 1 and maintaining 200 kHz at G = 100. Its laser-trimmed internal resistors ensure gain accuracy of ±0.01% (min) and low drift, while separate sense and reference terminals support remote sensing and precise output referencing.

Input protection circuitry withstands ±40 V continuously without damage, even with supplies off. The device supports dual-supply operation down to ±2.25 V and features independent, isolated channels with < –120 dB crosstalk at 1 kHz - critical for multi-sensor systems requiring channel-to-channel isolation.

Key Specifications

Pinout & Package

INA2128P is housed in a 16-pin SOIC (DW) package measuring 10.3 mm × 10.3 mm, with standard JEDEC MS-012AC footprint and 1.27 mm pitch. Thermal resistance R_θJA is 110°C/W, supporting operation up to +85°C ambient without forced airflow.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA2128P, INA2126P provides identical per-channel performance but requires duplicate placement for dual-channel needs, increasing PCB area and assembly cost; AD8226ARZ trades 4× higher offset and 7× higher drift for lower unit price, making it viable only in non-critical industrial monitoring where recalibration is routine.

Availability

INA2128P is available at Aetrix Electronics and suitable for pressure transmitters, ECG monitors, weigh scales, and analog input modules requiring stable component supply across industrial, medical, and test equipment programs.

Supply support for INA2128P 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 INA2128P belongs to TI's high-accuracy instrumentation amplifier product line, engineered specifically for low-drift, low-power sensor signal conditioning in industrial process control and medical diagnostics equipment.

FAQ

What is the maximum gain achievable with INA2128P, and how is it set?

The INA2128P supports gains from 1 V/V to 10,000 V/V, set by a single external resistor (R_G) connected between Pin 7 and ground. The gain equation is G = 1 + (50 kΩ / R_G). For G = 10,000, R_G = 5 Ω; for G = 1, R_G is left open. Layout care is required at high gains to minimize parasitic resistance in R_G traces, as wiring resistance directly impacts accuracy. The INA2128P datasheet specifies gain error as low as ±0.01% for G = 1.

Does INA2128P require external trimming for offset voltage?

No - the INA2128P is laser-trimmed at wafer level to achieve ≤50 µV max input offset voltage and ≤0.5 µV/°C drift, eliminating the need for external trim pots in most applications. Section 6.2.4 of the INA2128P datasheet shows an optional external op-amp circuit for fine-tuning output offset via the Ref terminal, but this is only necessary in ultra-high-precision systems demanding sub-10 µV residual error after calibration.

Can INA2128P operate from a single 5-V supply?

Yes - the INA2128P supports single-supply operation from 4.5 V to 36 V (per Recommended Operating Conditions). When using a 5-V rail, the input common-mode range is limited to approximately 2 V to 3 V (V_CM = (V–) + 2 to (V+) – 2), and output swing is typically 0.15 V above V– and 0.15 V below V+ (CSO: TID). For optimal performance at low supply, refer to Figure 5-10 in the INA2128P datasheet showing V_CM vs. V_O curves at ±2.5 V.

How does INA2128P handle input overvoltage conditions?

The INA2128P inputs are individually protected to ±40 V - meaning each input can withstand up to +40 V or –40 V relative to ground, even with power supplies disconnected. Internal protection limits input current to ~1.5–5 mA during overload, preventing damage. This eliminates external TVS diodes in pressure transmitter designs exposed to field-wiring faults. The INA2128P maintains functionality after such events, with no latch-up or parameter shift.

What is the channel-to-channel crosstalk specification for INA2128P?

The INA2128P exhibits < –120 dB typical crosstalk at 1 kHz (Figure 5-11), due to fully independent input bias networks, separate supply pins (V+ A/B, V– A/B), and isolated internal amplifiers. This enables simultaneous measurement of two unrelated signals - e.g., differential pressure and temperature in a single housing - without measurable interference. Layout best practices (guard traces, separated input routing) maintain this performance in production PCBs.