Texas Instruments THS3125ID

Overview

THS3125ID from Texas Instruments is a dual-channel, bipolar-input, current-feedback amplifier optimized for high-output-current, low-distortion video and instrumentation applications. It delivers 450 mA output drive, 128-MHz –3-dB bandwidth (RL = 50 Ω), 1550-V/µs slew rate (G = 2), 2.2-nV/√Hz voltage noise, and features a logic-controlled shutdown mode reducing quiescent current to 370 µA per channel - enabling power-sensitive industrial line drivers and piezo actuator interfaces.

For engineers reviewing the THS3125ID datasheet, THS3125ID pinout, THS3125ID application, or THS3125ID equivalent, key selection criteria include its HTSSOP-14 PowerPAD™ package thermal performance (θJA = 37.5°C/W), dual-channel independent shutdown control via REF/SHUTDOWN pins, ±5 V to ±15 V dual-supply operation, and verified differential gain error <0.01% in 75-Ω serially terminated video systems.

Technical Context

The THS3125ID uses a current-feedback architecture with high-impedance noninverting inputs (1.5 MΩ) and low-impedance inverting inputs (15 Ω), enabling wide bandwidth stability with minimal gain dependency on feedback resistor value. Its transimpedance open-loop gain exceeds 1 MΩ, supporting fast settling (64 ns to 0.1%) under heavy capacitive loads.

Shutdown functionality is implemented via a dedicated SHUTDOWN pin referenced to the internal REF pin, with enable/disable thresholds defined relative to REF (REF + 0.8 V / REF + 2 V). The REF pin accepts 0 V to (VCC+ − 4 V), allowing flexible biasing for rail-to-rail shutdown control across supply ranges.

Key Specifications

Pinout & Package

THS3125ID is housed in an HTSSOP-14 PowerPAD™ package (5.00 mm × 4.40 mm) with exposed thermal pad on underside requiring PCB copper connection for thermal management (θJA = 37.5°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with THS3125IPWP, THS3125ID offers identical performance in tube packaging for prototyping and low-volume builds; versus THS3095DR, THS3125ID provides integrated dual-channel operation with shutdown control - reducing component count and PCB area while enabling dynamic power optimization in multi-signal systems.

Availability

THS3125ID is available at Aetrix Electronics and suitable for video distribution, industrial line drivers, and piezo actuator driver applications requiring stable component supply, extended temperature support (−40°C to +85°C), and consistent HTSSOP-14 PowerPAD™ thermal performance.

Supply support for THS3125ID 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-speed amplifiers and precision signal chain solutions.

The THS3125ID belongs to TI's THS312x family of low-noise, high-output-current current-feedback amplifiers, designed specifically for demanding video, instrumentation, and reactive-load driving applications where bandwidth, drive strength, and distortion performance are critical.

FAQ

What is the maximum safe output current for THS3125ID?

The THS3125ID is rated for continuous output current up to 440 mA per channel into 25 Ω loads at ±15 V supply (T_A = +25°C), with absolute maximum rating of 550 mA. Sustained operation above 440 mA requires careful thermal design using the PowerPAD™ to maintain junction temperature below 150°C - verified via θ_JA = 37.5°C/W in the HTSSOP-14 package. THS3125ID must not be operated beyond its dissipation limits without adequate PCB copper area.

Does THS3125ID support single-supply operation?

Yes, THS3125ID supports single-supply operation from 10 V to 30 V (V_CC+ to GND), as specified in Recommended Operating Conditions. Input common-mode range extends to within 2.5 V of either rail (e.g., 0 V to +7.5 V at V_CC+ = 10 V), and output swing reaches within ~1.2 V of each rail under light loads. For optimal performance, especially in AC-coupled video applications, dual-supply ±5 V to ±15 V is recommended to maximize dynamic range and minimize offset-related distortion. THS3125ID's REF and SHUTDOWN pins remain functional across the full supply range.

How does the REF pin affect THS3125ID shutdown behavior?

The REF pin sets the reference voltage for THS3125ID's shutdown threshold: device enables when SHUTDOWN voltage falls below (REF + 0.8 V), and disables when SHUTDOWN rises above (REF + 2 V). If REF is left unconnected, it defaults to approximately mid-supply, establishing a predictable turn-on/off window. Driving REF to a fixed voltage (e.g., 0 V or V_CC−) allows precise rail-referenced shutdown control. THS3125ID's shutdown current drops to 370 µA per channel regardless of REF voltage, provided V_SHDN satisfies the threshold conditions.

Can THS3125ID drive 50-Ω transmission lines directly?

Yes, THS3125ID is explicitly characterized to drive 50-Ω loads with full performance: 26-VPP output swing, −80 dBc THD at 2 VPP/1 MHz, and 128-MHz bandwidth (RF = 470 Ω, G = 2). Its 450-mA output current capability ensures stable termination without external buffers. Layout best practices require short, controlled-impedance traces, local 0.1-µF ceramic decoupling at each V_CC+/V_CC− pin, and direct connection of the PowerPAD™ to a solid thermal plane. THS3125ID's low 14-Ω open-loop output resistance further enhances matching to 50-Ω systems.

What is the small-signal settling time specification for THS3125ID?

THS3125ID achieves 64 ns settling time to 0.1% for a 5-VPP step response under G = −1, ±15 V supply, and RL = 50 Ω conditions - verified per JEDEC JESD22-B117A. This performance is enabled by its current-feedback topology and high slew rate (1550 V/µs), making it suitable for fast data acquisition front-ends and pulse-amplification stages. Settling time degrades slightly at lower supplies (e.g., 53 ns at ±5 V) and increases with heavier loads or higher gains. THS3125ID's settling behavior is consistent across both channels, with channel-to-channel matching within 1 ns.