Texas Instruments OPA211AID

Overview

OPA211AID from Texas Instruments is a dual-channel, precision operational amplifier optimized for high-resolution data acquisition and low-noise signal conditioning. It delivers 1.1 nV/√Hz input voltage noise at 1 kHz, 700 ns 16-bit settling time over 10-V output swing, and rail-to-rail output with ±2.25 V to ±18 V dual-supply operation. It serves as a loop filter amplifier in PLLs and ADC driver in lab instrumentation.

For engineers reviewing the OPA211AID datasheet, OPA211AID pinout, OPA211AID application, or OPA211AID equivalent, key selection criteria include its 1.1-nV/√Hz noise floor, 80-MHz gain-bandwidth at G=100, shutdown functionality, SOIC-8 package compatibility, and performance across –40°C to +125°C industrial temperature range.

Technical Context

The OPA211AID implements a fully differential, high-speed precision op-amp architecture with internal compensation for unity-gain stability. Its low 1.1 nV/√Hz voltage noise and 1.7 pA/√Hz current noise enable high-fidelity amplification of weak sensor signals without degrading SNR.

It features an active high shutdown pin (Pin 8), rail-to-rail output stage capable of sourcing/sinking 30 mA, and robust common-mode rejection (120 dB) across 10 Hz–100 kHz. The device maintains 114 dB open-loop gain and 0.35 μV/°C offset drift over full temperature range.

Key Specifications

Pinout & Package

OPA211AID is supplied in an 8-pin SOIC (D) package with 4.90 mm × 3.90 mm body size and standard JEDEC MS-012 footprint. Thermal pad is not present in this variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with OPA211AID, OPA211AIDR offers identical performance in tape-and-reel format for volume manufacturing, while ADA4898-1ARMZ trades lower noise and higher speed for doubled supply current and loss of dual-channel integration and shutdown control.

Availability

OPA211AID is available at Aetrix Electronics and suitable for ultrasound scanner design, semiconductor test equipment development, and X-ray detector front-end applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for OPA211AID 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and communications markets.

The OPA211AID belongs to TI's precision op-amp product line, engineered specifically for high-resolution data acquisition, low-noise instrumentation, and demanding signal-chain applications where voltage noise, offset stability, and settling accuracy are critical.

FAQ

What is the maximum operating temperature range for the OPA211AID?

The OPA211AID is specified from –40°C to +125°C ambient temperature. This extended industrial temperature range ensures reliable operation in harsh environments such as medical imaging systems, factory automation controllers, and outdoor test equipment where thermal management is constrained. All key parameters-including offset drift (±0.35 μV/°C), open-loop gain (≥114 dB), and noise-are guaranteed across this full range. The OPA211AID maintains 16-bit settling performance even at +125°C.

Does the OPA211AID support single-supply operation?

Yes, the OPA211AID supports true single-supply operation from 4.5 V to 36 V. Its rail-to-rail output stage swings to within 200 mV of both supply rails under full load, and its input common-mode range extends to (V–)+1.8 V, enabling direct interfacing with ground-referenced sensors. When powered from +5 V or +12 V, the OPA211AID retains all key specifications including 1.1 nV/√Hz noise and 700 ns 16-bit settling-making it ideal for portable and space-constrained instrumentation using OPA211AID.

What is the purpose of Pins 1 and 5 on the OPA211AID SOIC package?

Pins 1 and 5 of the OPA211AID are designated NC (no internal connection). They have no electrical function and may be left unconnected or tied to any voltage between V– and V+. These pins are reserved for future device variants or mechanical alignment; routing traces or vias to them provides no benefit and risks unintended coupling. In PCB layout, they should be treated as isolated copper islands-consistent with TI's recommended practice for OPA211AID SOIC implementation.

How does the shutdown feature of the OPA211AID operate?

The OPA211AID shutdown pin (Pin 8) is active-high: applying ≥(V+)–0.35 V disables the amplifier, placing the output in high-impedance state and reducing quiescent current to ≤20 μA per channel. Enabling requires (V–) ≤ V_SHUTDOWN ≤ (V+)–3 V. Turn-on and turn-off times are 2 μs and 3 μs respectively. This feature enables dynamic power gating in battery-powered DAQ systems-allowing OPA211AID to enter ultra-low-power mode between acquisition cycles without external switches or sequencing.

Can the OPA211AID drive capacitive loads directly?

The OPA211AID can drive up to 100 pF capacitive load while maintaining stability and 0.0015% (16-bit) settling in 700 ns, as verified in TI's typical characteristics (Figure 28). For loads >100 pF, external isolation resistance (e.g., 10–100 Ω in series with the output) is recommended to prevent peaking or ringing. The device's 5 Ω open-loop output impedance at 1 MHz and robust phase margin ensure predictable behavior with moderate capacitive back-termination-critical when interfacing OPA211AID directly to ADC input capacitors or long PCB traces.