Texas Instruments THS4275D

Overview

THS4275D from Texas Instruments is a low-noise, high-slew-rate, unity-gain-stable voltage-feedback amplifier with power-down functionality. It delivers 1.4 GHz small-signal bandwidth (±5 V), –92 dBc THD at 30 MHz, 1000 V/μs slew rate, and operates from ±5 V or single 5–10 V supplies. It serves as a high-linearity ADC preamplifier in RF receiver signal chains requiring wide dynamic range and low distortion.

For engineers reviewing the THS4275D datasheet, THS4275D pinout, THS4275D application, or THS4275D equivalent, key selection criteria include its power-down enable interface, thermal oscillation limit at +60°C junction temperature, differential-to-single-ended conversion capability, and compatibility with 150 Ω/499 Ω load configurations per TI SLOS397F Rev. October 2009.

Technical Context

The THS4275D uses a voltage-feedback architecture optimized for unity-gain stability without external compensation. Its internal power-down circuit responds to logic-level signals applied to the PD pin relative to REF (0 V or VS+), enabling fast 4 μs turn-on and 3 μs turn-off transitions while reducing quiescent current to ≤1.2 mA.

It exhibits low input voltage noise (3 nV/√Hz) and current noise (3 pA/√Hz) at 1 MHz, supports rail-to-rail output swing under G = +2 (±3.7 V min, ±5 V supply), and maintains <0.01° differential phase error in video applications - all validated across –40°C to +85°C operating range.

Key Specifications

Pinout & Package

THS4275D is packaged in an 8-pin SOIC (D) with exposed thermal pad (PowerPAD™), requiring solder connection to a copper pour for thermal reliability. Pin 5 is dedicated PD (power-down control); Pin 1 is REF (reference for PD threshold).

Key Features

Applications

Equivalent & Alternatives

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

Compared with THS4271D and LMH6703MF, THS4275D uniquely combines ultra-low noise, high slew rate, and deterministic power-down control in a thermally managed SOIC package - making it the only option for precision, power-aware wideband amplification where junction temperature must remain ≤+60°C.

Availability

THS4275D is available at Aetrix Electronics and suitable for high-speed data acquisition, wireless infrastructure transceivers, broadcast video signal processing, and test equipment requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for THS4275D 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, embedded processing, and connectivity technologies, with over 90 years of innovation in high-performance signal chain solutions.

The THS4275D belongs to TI's high-speed operational 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 mandatory.

FAQ

What is the maximum junction temperature to prevent oscillation in the THS4275D?

The THS4275D must not exceed +60°C junction temperature to prevent low-level oscillation. This limit is strictly enforced by TI's characterization and applies regardless of supply voltage or gain configuration. Proper thermal design - including soldering the PowerPAD™ to a large PCB copper area - is essential to maintain safe operation under full load. The THS4275D datasheet (SLOS397F) explicitly defines this constraint in Section "Maximum Die Temperature to Prevent Oscillation".

How does the power-down function operate on the THS4275D?

The THS4275D power-down function is controlled via two pins: REF (Pin 1) and PD (Pin 5). When REF is grounded, PD ≥ +1.0 V enables normal operation; PD ≤ +1.0 V activates power-down. When REF is left floating or tied to VS+, PD ≤ VS+ – 1.7 V enables normal operation; PD ≥ VS+ – 1.0 V activates power-down. Quiescent current drops to ≤1.2 mA, and turn-off delay is 3 μs. This dual-threshold design eliminates external level-shifting circuitry.

Can the THS4275D drive a 150 Ω load while maintaining –92 dBc THD at 30 MHz?

Yes - the THS4275D achieves –92 dBc THD at 30 MHz specifically under RL = 150 Ω, VO = 1 VPP, and G = 1 conditions (TI SLOS397F, Table "ELECTRICAL CHARACTERISTICS: VS = ±5 V"). Its 110 mA sourcing capability and <0.1 Ω output impedance ensure minimal gain compression and harmonic generation into standard video and RF loads. Performance remains valid only when thermal design keeps TJ ≤ +60°C.

What is the small-signal bandwidth of the THS4275D at G = 2 and ±5 V supply?

The THS4275D delivers 390 MHz small-signal bandwidth at G = 2, VO = 100 mVPP, RL = 150 Ω, and ±5 V supply (TI SLOS397F, "ELECTRICAL CHARACTERISTICS" table). This value reflects usable gain-bandwidth tradeoff for intermediate-gain stages in IF amplifiers and active filters, and is measured under linear, non-saturated conditions with proper decoupling.

Is the THS4275D pin-compatible with the THS4271D?

No - the THS4275D and THS4271D are not pin-compatible. While both use the same SOIC-8 (D) package footprint, THS4275D repurposes Pin 1 as REF and Pin 5 as PD, whereas THS4271D uses Pin 1 as NC and Pin 5 as NC. Direct substitution would cause incorrect biasing or unintended power-down activation. Board redesign is required to migrate from THS4271D to THS4275D.