Texas Instruments OPA2227UAG4

Overview

OPA2227UAG4 from Texas Instruments is a dual, high-precision, low-noise operational amplifier in SOIC-8 package, delivering 3 nV/√Hz input voltage noise, 8 MHz gain bandwidth, and 2.3 V/µs slew rate. It operates from ±2.5 V to ±18 V supplies and is unity-gain stable, making it suitable for precision instrumentation front-ends, professional audio signal conditioning, and high-fidelity data acquisition systems.

For engineers reviewing the OPA2227UAG4 datasheet, OPA2227UAG4 pinout, OPA2227UAG4 application, or OPA2227UAG4 equivalent, key selection considerations include its dual-channel architecture, low 10 nA max input bias current, 138 dB CMRR, 160 dB open-loop gain, and guaranteed performance across –40°C to +85°C.

Technical Context

The OPA2227UAG4 implements a bipolar-input, fully differential input stage with laser-trimmed thin-film resistors enabling low offset voltage (±75 µV max) and ultra-low drift (±0.6 µV/°C max). Its unity-gain stability and internal compensation eliminate external phase-compensation components required by higher-speed variants like the OPA2228.

It supports rail-to-rail output swing within 2 V of supply rails at 10 kΩ load and maintains 120 dB CMRR down to –40°C, ensuring robust common-mode rejection in noisy industrial sensor interfaces and multi-stage analog signal chains.

Key Specifications

Pinout & Package

OPA2227UAG4 is housed in an 8-pin SOIC (Small Outline Integrated Circuit) package measuring 4.90 mm × 3.91 mm, optimized for surface-mount assembly and thermal performance (θ_JA = 101.9°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual high-precision op-amp applications.

Compared with OPA2188AIDR and AD8620ARZ, the OPA2227UAG4 uniquely balances low broadband noise, unity-gain stability, and bipolar-input linearity-making it the optimal dual op-amp for mixed-signal test equipment requiring both nanovolt DC accuracy and clean 100 kHz transient response.

Availability

OPA2227UAG4 is available at Aetrix Electronics and suitable for data acquisition systems, professional audio equipment, vibration analysis instruments, and power supply monitoring circuits requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for OPA2227UAG4 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 designing analog ICs, embedded processors, and connectivity solutions for industrial, automotive, and communications markets.

The OPAx22x product line targets high-precision analog signal chains demanding simultaneous low noise, wide bandwidth, and DC accuracy-specifically engineered for test & measurement, audio, and sensor interface applications.

FAQ

What is the maximum operating supply voltage for the OPA2227UAG4?

The OPA2227UAG4 supports a total supply voltage range of ±2.5 V to ±18 V, with absolute maximum ratings allowing up to ±18 V per rail (36 V total). Operation at ±18 V is fully specified across –40°C to +85°C, and the device remains functional up to ±20 V with derated performance. This wide range enables direct use in legacy ±15 V industrial systems and newer ±12 V or ±5 V portable designs without external regulators. The OPA2227UAG4 maintains 138 dB CMRR and 8 MHz GBW across this entire range.

Does the OPA2227UAG4 require external compensation capacitors?

No, the OPA2227UAG4 is internally compensated and unity-gain stable, eliminating the need for external compensation components. Its 8 MHz gain bandwidth and 2.3 V/µs slew rate are guaranteed under G = 1 conditions with standard 10 kΩ loads and 100 pF capacitive loads. Unlike the OPA2228, which requires minimum closed-loop gain ≥5, the OPA2227UAG4 can safely drive unity-gain followers, active filters, and ADC buffers without risk of oscillation-reducing BOM count and layout complexity in precision signal paths.

How does the OPA2227UAG4 handle input common-mode voltage range?

OPA2227UAG4 specifies a common-mode input voltage range of (V–) + 2 V to (V+) – 2 V, meaning it cannot accept inputs within 2 V of either supply rail. For example, with ±15 V supplies, valid input range is –13 V to +13 V. This limitation arises from its bipolar input stage and is consistent across temperature. To interface with rail-to-rail sensors, external level-shifting or supply adjustment is required. The device maintains 120 dB CMRR across this full specified range, ensuring accurate rejection of power supply ripple and ground noise in differential configurations.

What is the typical input voltage noise spectral density of the OPA2227UAG4 at 1 kHz?

The OPA2227UAG4 delivers a typical input voltage noise spectral density of 3 nV/√Hz at 1 kHz, matching its 10 Hz and 100 Hz values and confirming flat broadband noise behavior. This value is measured under standard conditions (T_A = 25°C, V_S = ±15 V, R_L = 10 kΩ) and is guaranteed across the full –40°C to +85°C operating range. At 0.1–10 Hz, integrated noise is 15 nV_RMS, making it suitable for low-frequency precision applications such as thermocouple amplification and DC-coupled strain gauge bridges where 1/f noise impacts measurement stability.

Is the OPA2227UAG4 pin-compatible with industry-standard op-amps?

Yes, the OPA2227UAG4 is a pin-for-pin replacement for the OP-27, LT1007, and MAX427 in SOIC-8 and PDIP-8 packages. Pin mapping matches standard dual op-amp conventions: pins 1/7 are outputs, 2/6 are inverting inputs, 3/5 are noninverting inputs, and 4/8 are V–/V+ supplies. No PCB changes are required when upgrading from these legacy parts. Texas Instruments explicitly states this compatibility in the datasheet, citing "substantial improvements across the board" including lower noise (3 nV/√Hz vs. OP-27's 3.5 nV/√Hz), higher CMRR (138 dB vs. 126 dB), and improved slew rate (2.3 V/µs vs. 2.0 V/µs).