Texas Instruments INA155UG4

Overview

INA155UG4 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 INA155UG4 datasheet, INA155UG4 pinout, INA155UG4 application, or INA155UG4 equivalent, this page delivers verified specifications, SOIC-8 package details, real-world use cases in bridge sensing and medical amplification, and validated alternative parts with documented functional trade-offs.

Technical Context

The INA155UG4 integrates two precision op-amps and laser-trimmed thin-film resistors in a three-op-amp topology optimized for low-voltage operation. Its rail-to-rail output stage uses complementary common-source transistors to achieve ≤10 mV swing from rails under 10 kΩ load, while internal gain-setting architecture enables pin-strapped selection between G = 10 (RG pins open) and G = 50 (RG pins shorted).

Input bias current is limited to ±10 pA across temperature, enabled by CMOS input stages with 10¹³ Ω || 3 pF impedance. Common-mode rejection exceeds 92 dB at G = 10 (0.6–3.7 VCM), degrading above (V+) – 1.8 V due to internal node saturation-requiring careful Ref pin and VCM coordination per application.

Key Specifications

Pinout & Package

INA155UG4 is housed in an SOIC-8 (Package Drawing D) surface-mount package with standard 1.27 mm pitch, 3.9 mm × 4.9 mm body, and JEDEC-standard pinout. Thermal resistance θJA = 150°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA155UG4, INA126UA offers flexible gain but sacrifices offset accuracy and output swing; AD8221ARMZ provides superior PSRR and supply flexibility but lacks rail-to-rail output-making INA155UG4 optimal for compact, low-voltage, fixed-gain sensor interfaces.

Availability

INA155UG4 is available at Aetrix Electronics and suitable for industrial sensor amplifiers, medical bio-signal front-ends, and A/D converter driver circuits requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for INA155UG4 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-accuracy signal chain components for industrial, medical, and test equipment markets.

The INA155 series was designed specifically for low-cost, single-supply instrumentation tasks-including bridge, RTD, and thermocouple amplification-where rail-to-rail output, low offset, and wide temperature range are essential.

FAQ

What is the maximum operating temperature range for the INA155UG4?

The INA155UG4 is fully specified over –55°C to +125°C and rated for operation from –65°C to +150°C. Its thermal resistance (θJA = 150°C/W) and SOIC-8 package enable reliable performance in under-hood automotive and industrial motor control environments where ambient temperatures exceed 100°C.

Can the INA155UG4 operate from a 3.3 V supply?

Yes, the INA155UG4 operates from +2.7 V to +5.5 V, making it fully compatible with 3.3 V systems. At 3.3 V, its output swings within 10 mV of rails, and input common-mode range extends from 0.2 V to 2.5 V-enabling direct interface with 3.3 V ADCs and microcontrollers without level-shifting circuitry.

How do I configure the INA155UG4 for G = 50?

To set G = 50 on the INA155UG4, short Pin 1 (RG) to Pin 8 (RG) using a low-impedance connection (<20 Ω). This configuration achieves <0.25% gain error at +25°C. Avoid long traces or series resistors, as >20 Ω impedance introduces measurable gain shift per the datasheet's application note.

Does the INA155UG4 require external offset trimming?

No-INA155UG4 is laser-trimmed to ±200 µV max input offset voltage, eliminating the need for external trimming in most applications. If fine adjustment is required, apply a correction voltage to the Ref pin (Pin 5), but ensure the source impedance remains <200 Ω to preserve CMRR performance.

What is the recommended decoupling for the INA155UG4 power pins?

Place a 0.1 µF ceramic capacitor between Pin 7 (V+) and Pin 4 (V–), located as close as possible to the SOIC-8 package. This minimizes high-frequency PSRR degradation and prevents oscillation when driving capacitive loads. For noisy supplies, add a 10 µF tantalum in parallel, placed near the board's main power entry point.