Texas Instruments THS4031IDR

Overview

THS4031IDR from Texas Instruments is a single-channel, ultra-low-noise, high-speed voltage-feedback operational amplifier optimized for precision wideband signal conditioning. It delivers 100MHz bandwidth (G = 2, –3dB), 100V/μs slew rate, 1.2nV/√Hz input voltage noise, –96dBc THD at 1MHz (RL = 1kΩ), and ±13.6V output swing - enabling high-fidelity buffering of 16-bit SAR ADCs in data acquisition systems.

For engineers reviewing the THS4031IDR datasheet, THS4031IDR pinout, THS4031IDR application, or THS4031IDR equivalent, key selection criteria include low-noise drive capability for high-resolution converters, offset nulling support for DC-critical stages, thermal performance in SOIC-8 packaging, and stability with capacitive loads up to 10pF without external compensation.

Technical Context

The THS4031IDR employs a complementary bipolar 30V process with GHz f_T transistors, yielding voltage-feedback architecture optimized for unity-gain stability (120MHz bandwidth) and fast settling (70ns to 0.1%). Its internal compensation prioritizes bandwidth and slew rate but requires series isolation resistors (>20Ω) when driving >10pF capacitive loads to maintain phase margin.

It operates from dual supplies (±4.5V to ±16V) or single supply (9V–32V), supports offset nulling via pins 1 and 8, and features rail-to-rail input common-mode range (±14.3V at ±15V supply) with 95dB CMRR and 95dB PSRR at 25°C - making it suitable for mixed-signal front-ends where noise, distortion, and DC accuracy coexist.

Key Specifications

Pinout & Package

THS4031IDR is packaged in an 8-pin SOIC (D package), 4.9mm × 6mm body size, with exposed thermal pad not present (HVSSOP/DGN variant has pad; SOIC does not). Pin functions are validated per TI SLOS224L datasheet Rev. July 2024.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed, low-noise amplifier applications.

Compared with THS4031IDR, OPA637BP trades lower cost and legacy availability for higher noise and missing nulling; LMH6629MF/NOPB offers superior noise and speed but sacrifices DC adjustability and increases power draw - making THS4031IDR optimal for precision wideband analog front-ends requiring both AC fidelity and DC tunability.

Availability

THS4031IDR is available at Aetrix Electronics and suitable for high-performance data acquisition, ultrasound imaging, video line driving, and active filter design requiring stable component supply across industrial temperature ranges (–40°C to +85°C).

Supply support for THS4031IDR 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 delivering analog, embedded processing, and connectivity solutions with deep expertise in high-speed precision amplifiers and signal chain ICs.

The THS403x product line was designed specifically for low-noise, wideband signal conditioning in communications, imaging, and test equipment - emphasizing voltage-feedback architecture, DC adjustability, and robust drive capability.

FAQ

What is the maximum recommended capacitive load for THS4031IDR without external isolation?

The THS4031IDR is internally compensated for optimal bandwidth and slew rate, but stability degrades with >10pF capacitive loading directly at the output. To avoid high-frequency ringing or oscillation, always use a minimum 20Ω series resistor between the THS4031IDR output and any load exceeding 10pF - including PCB traces, connectors, and ADC input capacitance. This isolation maintains phase margin while preserving signal integrity.

Does THS4031IDR support single-supply operation, and what is the minimum voltage?

Yes, THS4031IDR supports true single-supply operation from 9V to 32V (V_CC = V₊ to GND). At 9V, it delivers usable performance: 90MHz bandwidth, 80V/μs slew rate, and ±3.5V output swing into 1kΩ. Input common-mode range extends to within 1.2V of GND, enabling DC-coupled operation with proper biasing - verified per TI SLOS224L Section 5.3.

How is offset nulling implemented on THS4031IDR, and what potentiometer value is recommended?

Offset nulling on THS4031IDR uses pins 1 and 8 (NULL) connected to opposite ends of a 10kΩ linear-taper potentiometer, with the wiper tied to V_CC–. This configuration allows trimming input offset voltage to <50μV. The potentiometer must be low-noise, low-TC (e.g., cermet), and placed close to the device. Do not connect NULL pins directly to supply rails - doing so disables nulling and may increase offset drift.

What thermal considerations apply to THS4031IDR in SOIC-8 (D) package?

In SOIC-8 (D) package, THS4031IDR has R_θJA = 124.5°C/W (no airflow). At 7.5mA supply current and ±15V operation, power dissipation is ~0.225W, resulting in ~28°C junction rise above ambient. For continuous 85°C ambient operation, junction temperature reaches ~113°C - within the 130°C long-term reliability limit. Use 2–4 thermal vias under the exposed pad area (if using DGN variant) or copper pour on SOIC leads to reduce R_θJB.

Can THS4031IDR drive a 150Ω load at full output swing, and what is the resulting THD?

Yes, THS4031IDR drives 150Ω loads with ±12.9V swing at ±15V supply (Section 5.6). Under these conditions, THD is –81dBc at 1MHz (RL = 150Ω), confirmed in TI SLOS224L Table 5-6. This performance supports video line driving and high-speed DAC output buffering where 75Ω/150Ω termination is required - though THD degrades by ~15dB versus 1kΩ load due to increased current-induced distortion.