Texas Instruments INA155EA/250

Overview

INA155EA/250 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 - ideal for precision bridge sensor conditioning in industrial control systems.

For engineers reviewing the INA155EA/250 datasheet, INA155EA/250 pinout, INA155EA/250 application, or INA155EA/250 equivalent, key selection considerations include its MSOP-8 package, low 0.2 pA typical input bias current, 6.5 V/µs slew rate, rail-to-rail output swing within 10 mV of rails, and internal gain-setting architecture requiring no external resistors for G = 10 or G = 50 configurations.

Technical Context

The INA155EA/250 employs a three-op-amp topology with complementary CMOS input stages enabling rail-to-rail common-mode input operation outside the (V+) – 1.8 V to (V+) – 0.8 V transition region. Its gain is set by strapping pins 1 and 8 - open for G = 10, shorted for G = 50 - eliminating external resistor tolerance dependence in base configurations.

Internal laser trimming ensures ±200 µV max input offset voltage and ±5 µV/°C drift across temperature. The output stage uses a class AB common-source structure delivering rail-to-rail swing into ≥10 kΩ loads while maintaining <0.1% gain error, and supports direct driving of capacitive-input ADCs such as the ADS7818.

Key Specifications

Pinout & Package

The INA155EA/250 is housed in an 8-pin VSSOP (MSOP-8) package (drawing DGK), measuring 3.0 mm × 3.0 mm × 1.0 mm, with exposed thermal pad for enhanced power dissipation. Pin 1 is marked with a dot; pin numbering follows standard MSOP convention (counterclockwise from dot).

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA155EA/250, INA126PA trades bandwidth and output swing for lower unit cost in non-rail-to-rail applications, while AD8221ARMZ provides superior DC precision at the expense of single-supply compatibility and increased supply headroom requirements.

Availability

INA155EA/250 is available at Aetrix Electronics and suitable for industrial sensor amplifiers, medical biopotential front-ends, and portable data acquisition systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for INA155EA/250 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 full product support, manufacturing, and documentation for the INA155 family.

The INA155 product line was designed specifically for low-voltage, single-supply precision instrumentation tasks - emphasizing rail-to-rail output, ultra-low input bias current, and simplified gain configuration in space-constrained applications.

FAQ

What is the operating temperature range for the INA155EA/250?

The INA155EA/250 is fully specified over –55°C to +125°C, with guaranteed performance including offset voltage, CMRR, and bandwidth across this extended industrial range. Its operating range extends to –65°C to +150°C, and storage range matches that. This makes the INA155EA/250 suitable for under-hood automotive, downhole, and factory-floor applications where ambient extremes are expected.

How is gain configured on the INA155EA/250?

Gain on the INA155EA/250 is set by strapping pins 1 (RG) and 8 (RG): leaving them open configures G = 10 V/V, while shorting them sets G = 50 V/V. No external resistors are needed for these two standard gains. For intermediate gains (10 < G < 50), a resistor RG is placed between pins 1 and 8 per the equation G = 10 + 400 kΩ/(10 kΩ + RG). The INA155EA/250's internal laser trimming ensures <0.1% gain error at G = 10.

Does the INA155EA/250 require external offset trimming?

No - the INA155EA/250 is laser trimmed at wafer level to achieve ±200 µV maximum input offset voltage at +25°C and ±2 mV over temperature (–55°C to +125°C), eliminating the need for external trimming in most applications. If fine adjustment is required, offset can be adjusted via the Ref pin, where a correction voltage is algebraically added to the output: VOUT = (VIN+ − VIN−) × G + VREF.

What package type is used for the INA155EA/250?

The INA155EA/250 uses the VSSOP-8 (also known as MSOP-8) package with drawing code DGK, measuring 3.0 mm × 3.0 mm × 1.0 mm and featuring an exposed thermal pad. It is supplied in tape-and-reel format with 250 units per reel (orderable as INA155EA/250), RoHS-compliant, and rated MSL Level-2-260°C-1 year per JEDEC J-STD-020.

Can the INA155EA/250 drive ADC inputs directly?

Yes - the INA155EA/250 is explicitly characterized for direct driving of capacitive-input ADCs such as the ADS7818. Its 6.5 V/µs slew rate, 5 µs 0.1% settling time (G = 10), rail-to-rail output, and low output impedance at high frequencies enable robust interface without an external buffer. TI's Figure 9 in the INA155 datasheet demonstrates this capability with a 12-bit, 500 kSPS ADC.