Texas Instruments OPA191IDGKT

Overview

OPA191IDGKT from Texas Instruments is a single-channel, 36-V, precision CMOS operational amplifier with rail-to-rail input/output, ±5 µV offset voltage, ±5 pA input bias current, and 2.5-MHz gain-bandwidth product. It operates from ±2.25 V to ±18 V (4.5 V to 36 V), delivers ±65 mA output drive, and is used in high-accuracy analog input modules and data acquisition systems requiring low drift and EMI-filtered inputs.

For engineers reviewing the OPA191IDGKT datasheet, OPA191IDGKT pinout, OPA191IDGKT application, or OPA191IDGKT equivalent, this page provides verified package mapping (VSSOP-8), confirmed thermal metrics (R_θJA = 180.4°C/W), real-world capacitive load drive capability (1 nF), and precise alternative selection guidance for industrial signal conditioning designs.

Technical Context

The OPA191IDGKT implements a precision e-trim™ architecture enabling ultra-low offset drift (±0.1 µV/°C) and high common-mode rejection (140 dB). Its differential input voltage range extends to the supply rails, supporting direct sensing in high-voltage multiplexed DAQ front-ends without external level-shifting.

It features robust output stage design with 5 V/µs slew rate, 700 Ω open-loop output impedance at 1 MHz, and stable operation into 1-nF capacitive loads-critical for driving anti-aliasing filters and long traces in lab instrumentation and pressure transmitters.

Key Specifications

Pinout & Package

VSSOP-8 (DGK) package: 3.00 mm × 3.00 mm body, 0.65 mm pitch, exposed pad optional (not electrically connected in OPA191IDGKT).

Key Features

Applications

Equivalent & Alternatives

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

Compared with OPA191IDGKT, OPA189IDBVT offers superior DC precision but sacrifices output drive and capacitive load capability, while ADA4522-1ARMZ delivers near-zero drift at the cost of bandwidth and slew performance-making OPA191IDGKT optimal for balanced high-voltage, high-accuracy, high-speed signal conditioning.

Availability

OPA191IDGKT is available at Aetrix Electronics and suitable for analog input modules, data acquisition systems, and pressure transmitters requiring stable component supply across extended temperature ranges (–40°C to +125°C) and long production lifecycles.

Supply support for OPA191IDGKT 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 OPAx191 family was designed for high-voltage industrial signal conditioning-specifically targeting precision, low-power, rail-to-rail operation in harsh environments with EMI exposure and wide temperature swings.

FAQ

What is the maximum capacitive load the OPA191IDGKT can drive stably?

The OPA191IDGKT is characterized to drive up to 1 nF capacitive load without requiring external compensation. This capability is validated across temperature (–40°C to +125°C) and supply conditions (±2.25 V to ±18 V), making it suitable for direct connection to multi-pole anti-aliasing filters in data acquisition systems. Stability is maintained without series isolation resistors, reducing component count and board space in compact analog front-ends.

Does the OPA191IDGKT support rail-to-rail input with common-mode voltage beyond the supply rails?

No-the OPA191IDGKT supports rail-to-rail input with common-mode voltage ranging from (V–) – 0.1 V to (V+) + 0.1 V, as specified in the absolute maximum ratings. While its differential input voltage range extends to (V+) – (V–) + 0.2 V, the common-mode voltage must remain within the stated 0.1-V margin beyond the rails to avoid damage or parametric degradation. This is confirmed in Section 6.1 of the SBOS701D datasheet.

What is the thermal resistance (R_θJA) of the OPA191IDGKT in its VSSOP-8 package?

The junction-to-ambient thermal resistance (R_θJA) for the OPA191IDGKT in the DGK (VSSOP-8) package is 180.4°C/W, measured under standard JEDEC JESD51-2 conditions on a 2-layer board with 1-in² copper area. This value is critical for thermal design in enclosed industrial enclosures; derating is required above 85°C ambient to maintain junction temperature below 150°C.

Can the OPA191IDGKT operate from a single 5-V supply?

Yes-the OPA191IDGKT supports single-supply operation from 4.5 V to 36 V. At 5 V, it delivers rail-to-rail input/output swing, 2.2-MHz gain-bandwidth, and 140 µA quiescent current. Common-mode input range spans 0.1 V to 4.9 V, and output swings within 15 mV of each rail under no load, enabling full utilization of 5-V ADC references in portable instrumentation.

How does the EMI/RFI filtering in the OPA191IDGKT improve system-level immunity?

The OPA191IDGKT integrates on-chip EMI/RFI filters on both inputs, attenuating high-frequency interference (e.g., 433 MHz ISM band emissions from wireless sensors) before it reaches the input stage. This reduces susceptibility-induced offset shifts and output ripple in sensitive applications like train control systems and lab-grade DAQ-verified by TI's EMC test reports showing >40 dB suppression at 900 MHz without external ferrites or RC networks.