Texas Instruments OPA277UG4

Overview

OPA277UG4 from Texas Instruments is a single high-precision operational amplifier designed for low-drift, low-noise signal conditioning in measurement front-ends. It delivers 10 µV max input offset voltage, ±0.1 µV/°C drift, 134 dB open-loop gain, and operates from ±2 V to ±18 V supplies - enabling use in weigh scales, temperature transmitters, and precision data acquisition systems where DC accuracy dominates.

For engineers reviewing the OPA277UG4 datasheet, OPA277UG4 pinout, OPA277UG4 application, or OPA277UG4 equivalent, this page provides verified specifications, SOIC-8 package mapping, trim-capable pin functions, real-world thermal and noise performance data, and two validated alternative op amps with documented functional trade-offs.

Technical Context

The OPA277UG4 uses a laser-trimmed bipolar input stage with internal bias current cancellation, eliminating need for external compensation resistors. Its offset trim pins (1 and 8) support fine-tuning in ultra-stable applications, while input protection includes 1-kΩ series resistors and diode clamps rated for ±30-V differential overvoltage.

It is unity-gain stable, phase-inversion-free, and specified across ±5 V to ±15 V supply range with consistent 134 dB AOL, 140 dB CMRR, and 130 dB PSRR - unlike legacy op amps limited to single-supply test conditions. Thermal design is supported by R_θJA = 110.1°C/W (SOIC-8) and junction-to-board resistance of 52.3°C/W.

Key Specifications

Pinout & Package

OPA277UG4 is supplied in an 8-pin SOIC (D package), 3.91 mm × 4.90 mm body size, with exposed pad not present (non-thermal variant). Pin 1 is marked with a dot or notch indicator; pin numbering follows standard IC convention (counterclockwise from top-left corner).

Key Features

Applications

Equivalent & Alternatives

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

Compared with OPA277UG4, OPA2277UA offers channel integration without sacrificing precision, while OPA2189IDR trades higher 1/f noise for near-zero drift - making OPA277UG4 optimal for balanced low-noise, low-drift, and cost-sensitive industrial signal chains.

Availability

OPA277UG4 is available at Aetrix Electronics and suitable for weigh scale front-ends, temperature transmitters, and precision data acquisition modules requiring stable component supply across extended industrial temperature ranges and multi-year production cycles.

Supply support for OPA277UG4 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 heritage in precision op amp design and industrial-grade reliability.

The OPAx277 product line was engineered specifically for high-accuracy DC-critical applications - replacing OP-177 with improved noise, wider output swing, and half the quiescent current while maintaining pin compatibility and laser-trimmed stability.

FAQ

What is the maximum supply voltage for OPA277UG4?

The OPA277UG4 supports a total supply voltage (V+ to V−) of up to 36 V, corresponding to dual supplies of ±18 V. Absolute maximum ratings specify that exceeding ±18 V risks permanent damage. Operation at ±15 V is recommended for guaranteed specification compliance across –40°C to +85°C ambient temperature, and the device maintains key parameters (e.g., offset, CMRR) consistently from ±5 V to ±15 V per TI's real-world specification methodology.

Does OPA277UG4 require external bias current compensation?

No, OPA277UG4 does not require external bias current compensation. Its input stage incorporates internal bias current cancellation, resulting in ≤1 nA max input bias current and matched input offset current. Adding an external compensation resistor (e.g., R_comp = R_in || R_f) would degrade offset voltage and increase noise - contrary to best practice for this device. The datasheet explicitly states "no external bias current cancellation resistor" is needed.

Can OPA277UG4 drive capacitive loads?

Yes, OPA277UG4 can drive moderate capacitive loads, but stability depends on configuration. With unity-gain feedback and no isolation resistor, it remains stable up to ~100 pF. For larger loads (e.g., 1500 pF), a small series resistor (10–50 Ω) between output and load restores phase margin - as demonstrated in Figure 6-19 and 6-22 of the datasheet. Output overshoot increases with capacitance, so layout decoupling and load isolation must be verified per target CL.

What is the purpose of Pins 1 and 8 on OPA277UG4?

Pins 1 and 8 on OPA277UG4 are dedicated offset voltage trim terminals. They allow external adjustment of input offset using a 20-kΩ potentiometer (as shown in Figure 7-1), enabling fine nulling in applications demanding sub-5 µV residual offset. These pins are inactive unless connected; leaving them floating maintains the factory-laser-trimmed performance (±20 µV max). Trim is only recommended for the OPA277 single version - dual/quad variants lack these pins.

How does OPA277UG4 compare to OP-07 in practical designs?

OPA277UG4 replaces OP-07 with measurable improvements: 2× lower offset drift (±0.1 µV/°C vs ±0.3 µV/°C), 10× lower 0.1–10 Hz noise (0.22 µV_PP vs ~2.5 µV_PP), 50% lower quiescent current (800 µA vs 1.6 mA), and wider supply range (±2 V to ±18 V vs ±3 V to ±18 V). Unlike OP-07, OPA277UG4 features built-in input protection (±30 V differential tolerance) and eliminates need for external bias compensation - simplifying layout and improving long-term stability in field-deployed equipment.