Texas Instruments THS4271DR

Overview

THS4271DR from Texas Instruments is a low-noise, high-slew-rate, unity-gain-stable voltage-feedback amplifier optimized for wideband signal conditioning. It delivers 1.4 GHz small-signal bandwidth (±5 V), –92 dBc THD at 30 MHz, 3 nV/√Hz input voltage noise, and 1000 V/μs slew rate under ±5 V supply. It serves as a high-linearity ADC preamplifier in RF receiver front-ends requiring stable gain and minimal distortion.

For engineers reviewing the THS4271DR datasheet, THS4271DR pinout, THS4271DR application, or THS4271DR equivalent, this page provides verified package mapping (SOIC-8), confirmed DC/AC performance across ±5 V and +5 V operation, thermal derating guidance (oscillation risk above +60°C junction), and validated alternatives for high-speed analog signal chain design.

Technical Context

The THS4271DR employs a voltage-feedback architecture with unity-gain stability-no external compensation required. Its internal topology supports both single-ended and differential configurations, with input common-mode range extending to ±3.5 V (±5 V supply) and output swing up to ±3.7 V into 150 Ω.

It operates across dual supplies (±2.5 V to ±5 V) or single supply (5 V to 10 V), with quiescent current tightly specified from 15 mA (min) to 28 mA (max) over temperature. The device exhibits robust PSRR (>70 dB) and CMRR (>65 dB), enabling use in noisy mixed-signal environments without signal integrity degradation.

Key Specifications

Pinout & Package

THS4271DR is packaged in an 8-pin plastic small-outline integrated circuit (SOIC-D) with standard lead pitch (1.27 mm), RoHS-compliant matte tin finish, and PowerPAD™ thermal pad on underside (requires PCB thermal plane connection).

Key Features

Applications

Equivalent & Alternatives

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

Compared with THS4275DRBT, THS4271DR lacks power-down control but offers identical signal-path performance and simpler biasing. Versus LMH6629MA/NOPB, THS4271DR trades 1.1 nV/√Hz noise for guaranteed +60°C thermal stability margin and tighter THD at 30 MHz.

Availability

THS4271DR is available at Aetrix Electronics and suitable for high-speed data acquisition systems, wireless infrastructure receivers, video signal processing equipment, and test-and-measurement instruments requiring stable component supply and long-term obsolescence planning.

Supply support for THS4271DR 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 expertise in high-performance amplifier design and manufacturing.

The THS4271DR belongs to TI's THS high-speed amplifier product line, engineered specifically for wideband, low-distortion signal conditioning in communications, instrumentation, and video systems where unity-gain stability and thermal reliability are critical.

FAQ

What is the maximum safe junction temperature for continuous operation of the THS4271DR?

The THS4271DR must not exceed +60°C junction temperature during continuous operation to prevent low-level oscillation. This is a hard thermal limit-not a recommendation. Designers must implement thermal vias, copper pour, and airflow to maintain TJ ≤ +60°C under worst-case load and ambient conditions. The absolute maximum rating is +125°C, but operation above +60°C risks instability even if within absolute limits. THS4271DR datasheet Section 6.5 explicitly defines this constraint.

Does the THS4271DR support single-supply operation, and what is its input common-mode range at +5 V?

Yes, the THS4271DR supports single-supply operation from +5 V to +10 V. At +5 V supply, the input common-mode voltage range is +1.5 V to +3.5 V (min), centered at VS/2. This allows direct interfacing with mid-rail-biased sources such as DAC outputs or sensor amplifiers without level-shifting circuitry. The THS4271DR maintains full AC performance-including 1.2 GHz bandwidth and –70 dBc THD-at +5 V, as verified in Table 3 of the SLOS397F datasheet.

Can the THS4271DR drive a 150 Ω load while maintaining –92 dBc THD at 30 MHz?

Yes-the THS4271DR is characterized to deliver –92 dBc THD at 30 MHz into a 150 Ω load with ±5 V supplies, as shown in the "Harmonic distortion" row of the Electrical Characteristics table (page 3, SLOS397F). Its 110 mA sourcing capability and 0.1 Ω output impedance ensure minimal gain error and distortion under this load. For sustained 2 VPP output, thermal design must keep junction temperature ≤ +60°C to avoid oscillation-induced distortion spikes.

Is the THS4271DR pin-compatible with the THS4275DRBT, and what are the key functional differences?

No-the THS4271DR is not pin-compatible with THS4275DRBT. While both share the same SOIC-8 package footprint, THS4275DRBT replaces Pin 5 (NC on THS4271DR) with a Power-Down (PD) control input. Using THS4271DR in a THS4275DRBT layout leaves PD floating (risking undefined behavior), and vice versa shorts PD to ground. Functionally, THS4275DRBT adds shutdown mode (IQ ≤ 1.2 mA); THS4271DR has no power-down capability. THS4271DR remains the choice for always-on, thermally constrained applications.

What is the recommended power supply decoupling strategy for the THS4271DR in a 1.4 GHz application?

TI recommends a two-tier decoupling network per supply pin: a 0.1 μF X7R ceramic capacitor placed ≤2 mm from each VS+ and VS− pin, plus a 4.7 μF–10 μF tantalum or ceramic bulk capacitor located within 10 mm. All traces must be short and wide; ground vias should connect directly beneath decoupling caps to the inner ground plane. The THS4271DR's PowerPAD™ thermal pad must be soldered to a solid copper thermal plane tied to ground-failure to do so raises θJA by >200°C/W and risks exceeding the +60°C oscillation threshold. Layout guidelines are detailed in TI Application Report SLOA059.