Texas Instruments INA155EA/2K5

Overview

INA155EA/2K5 from Texas Instruments (formerly Burr-Brown) is a single-supply, rail-to-rail output CMOS instrumentation amplifier with fixed gain options of 10 V/V or 50 V/V, ±200 µV max input offset voltage, ±5 µV/°C offset drift, and 550 kHz bandwidth at G = 10. It operates from +2.7 V to +5.5 V and is specified over –55°C to +125°C for industrial sensor signal conditioning.

For engineers reviewing the INA155EA/2K5 datasheet, INA155EA/2K5 pinout, INA155EA/2K5 application, or INA155EA/2K5 equivalent, key selection criteria include its low input bias current (0.2 pA typ), high CMRR (100 dB at G = 10), rail-to-rail output swing within 10 mV of rails, and MSOP-8 package suitability for space-constrained precision analog front-ends.

Technical Context

The INA155EA/2K5 integrates two high-impedance CMOS input amplifiers (A1, A2) and a precision output stage in a three-op-amp topology. Its gain is set by internal resistor networks - open pins 1 and 8 yield G = 10; shorting them yields G = 50 - eliminating external gain-setting resistors for standard configurations.

It features rail-to-rail output via a class-AB common-source stage, supports reference-based output level shifting via the Ref pin, and includes ESD-protected inputs with diode clamping. Input common-mode range depends on gain configuration and reference voltage, with defined limits to maintain CMRR and linearity.

Key Specifications

Pinout & Package

INA155EA/2K5 is housed in an 8-pin MSOP (VSSOP-8, package drawing DGK), measuring 3.0 mm × 3.0 mm × 1.0 mm, with exposed thermal pad for enhanced power dissipation in high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD8221ARMZ and INA333AIDRGT, the INA155EA/2K5 uniquely balances low-cost, rail-to-rail output, 550 kHz bandwidth at G = 10, and –55°C to +125°C operation in a space-saving MSOP-8 - making it the most integrated solution for ruggedized, single-supply industrial signal chains.

Availability

INA155EA/2K5 is available at Aetrix Electronics and suitable for industrial sensor amplifiers, medical biopotential monitoring, and PCMCIA data acquisition requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for INA155EA/2K5 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 acquired Burr-Brown in 2000 and maintains its precision analog portfolio, emphasizing high-performance, low-power, and robust industrial-grade signal conditioning ICs.

The INA155 product line was designed specifically for cost-effective, single-supply instrumentation amplifier applications in harsh environments - targeting bridge, RTD, and thermocouple sensor interfaces where rail-to-rail output and wide temperature operation are critical.

FAQ

What gain options does the INA155EA/2K5 support, and how are they configured?

The INA155EA/2K5 supports two factory-set gain options: 10 V/V and 50 V/V. Gain is selected by pin strapping - leaving pins 1 and 8 unconnected configures G = 10; shorting them together configures G = 50. No external resistors are needed for these standard gains, simplifying layout and improving accuracy versus resistor-based alternatives. The INA155EA/2K5 datasheet confirms this behavior across –55°C to +125°C.

Is the INA155EA/2K5 suitable for single-supply operation at 3.3 V?

Yes, the INA155EA/2K5 is fully specified for single-supply operation from +2.7 V to +5.5 V, including 3.3 V systems. Its rail-to-rail output swings within 10 mV of both rails under 10 kΩ load, and its input common-mode range extends down to 0.2 V above V– at 2.7 V supply - enabling direct interface to 3.3 V ADCs without level-shifting circuitry. This capability is validated in the INA155EA/2K5 specifications table.

What is the maximum operating temperature range for the INA155EA/2K5?

The INA155EA/2K5 is specified over –55°C to +125°C, with extended operating range up to +150°C. This wide temperature rating is confirmed in the Absolute Maximum Ratings and Specifications tables of the official INA155EA/2K5 datasheet. Its guaranteed performance across this range makes it suitable for under-hood automotive, downhole oil & gas, and industrial control applications where ambient temperatures exceed standard commercial limits.

Does the INA155EA/2K5 require external components for basic operation?

No - the INA155EA/2K5 requires only bypass capacitors (e.g., 0.1 µF near V+ and V–) for stable operation. Gain is set internally via pin strapping (pins 1 and 8), and output level is controlled by the Ref pin voltage. Unlike general-purpose op-amps, it needs no external feedback or gain-setting resistors for G = 10 or G = 50. This integration is explicitly documented in the INA155EA/2K5 Applications Information section.

How does the INA155EA/2K5 handle input bias current return paths?

The INA155EA/2K5 has ultra-low input bias current (0.2 pA typ), but a return path for both inputs is mandatory to prevent saturation. For low-impedance sources (e.g., bridge sensors), connecting one input to a bias voltage suffices; for high-impedance sources (e.g., thermocouples), matched resistors to a common bias point ensure balanced operation and minimize offset. This requirement is detailed in the INA155EA/2K5 Application Information section on "Input Bias Current Return."