Texas Instruments THS3125IDRG4

Overview

THS3125IDRG4 from Texas Instruments is a dual-channel, bipolar-input current feedback amplifier optimized for high-output-current, low-distortion video and instrumentation signal conditioning. It delivers 450 mA output drive, 128-MHz –3-dB bandwidth (RL = 50 Ω), 1550-V/µs slew rate (G = 2), and 2.2-nV/√Hz input voltage noise - enabling clean 26-VPP differential output into 50-Ω loads for broadcast-grade video distribution.

For engineers reviewing the THS3125IDRG4 datasheet, THS3125IDRG4 pinout, THS3125IDRG4 application, or THS3125IDRG4 equivalent, key selection criteria include shutdown-enabled power management (370 µA quiescent per channel), dual-channel crosstalk performance (–67 dBc at 1 MHz), and HTSSOP-14 PowerPAD™ thermal packaging for high-power-density analog front-ends.

Technical Context

The THS3125IDRG4 implements a current feedback architecture with high-impedance noninverting inputs (1.5 MΩ) and low-impedance inverting inputs (15 Ω), enabling wide-bandwidth gain-setting via external feedback resistors without stability degradation. Its bipolar input stage provides symmetrical ±12.7-V common-mode input range (±15-V supplies) and low offset drift (10 µV/°C).

Shutdown control is implemented via a dedicated SHUTDOWN pin referenced to the REF pin, with enable/disable thresholds defined relative to REF (REF + 0.8 V enable, REF + 2 V disable). The REF pin accepts voltages from VCC− to VCC+ − 4 V, allowing flexible biasing for single- or dual-supply systems.

Key Specifications

Pinout & Package

THS3125IDRG4 is housed in a 14-pin HTSSOP PowerPAD™ package (5.00 mm × 4.40 mm) with exposed thermal pad on underside for enhanced heat dissipation. The PowerPAD must be soldered to a PCB copper plane for reliable operation at full output current.

Key Features

Applications

Equivalent & Alternatives

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

Compared with THS3125IPWP, THS3125IDRG4 adds RoHS/Green compliance and updated reel packaging; compared with THS3095DR, it trades single-channel speed for integrated dual-channel operation, power management, and superior thermal handling in space-constrained designs.

Availability

THS3125IDRG4 is available at Aetrix Electronics and suitable for video distribution systems, instrumentation signal chains, and high-speed line drivers requiring stable component supply, long-term lifecycle support, and traceable sourcing for industrial OEM programs.

Supply support for THS3125IDRG4 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 amplifiers and signal chain solutions.

The THS3125IDRG4 belongs to TI's THS312x family of low-noise, high-output-current current feedback amplifiers, designed specifically for demanding video, instrumentation, and high-fidelity analog interface applications where bandwidth, drive strength, and distortion performance are critical.

FAQ

What is the maximum safe output current for THS3125IDRG4?

The THS3125IDRG4 is rated for continuous output current up to 440 mA per channel under recommended operating conditions (±15 V, TA = +25°C, RL = 25 Ω). Absolute maximum rating is 550 mA, but sustained operation above 440 mA risks thermal overload unless PCB thermal design exceeds 3.3 W power dissipation capacity - verified via the HTSSOP PowerPAD™ layout guidelines in TI's SLMA002 technical brief. THS3125IDRG4 must be used with proper thermal vias and copper pour.

Does THS3125IDRG4 support single-supply operation?

Yes, THS3125IDRG4 supports single-supply operation from 10 V to 30 V. When operated with VCC− tied to ground, the input common-mode range extends from 0 V to VCC+ − 2.5 V (at ±5 V equiv), and output swing reaches up to 13.3 VPP into 50 Ω. The REF pin must be biased within VCC− to VCC+ − 4 V to ensure correct shutdown threshold behavior - e.g., tie REF to 2.5 V for a 5-V system. THS3125IDRG4 maintains full AC performance in this configuration.

How does the REF pin affect THS3125IDRG4 shutdown behavior?

The REF pin sets the reference voltage for the THS3125IDRG4 shutdown comparator. Enable occurs when SHUTDOWN voltage falls below REF + 0.8 V; disable occurs when SHUTDOWN rises above REF + 2 V. REF itself can be set anywhere from VCC− to VCC+ − 4 V - allowing adaptive thresholding in varying supply conditions. If REF is left floating, internal leakage may cause undefined shutdown states; TI specifies grounding REF only if shutdown is unused. THS3125IDRG4 requires explicit REF biasing for predictable low-power operation.

What is the small-signal bandwidth of THS3125IDRG4 at G = 1?

At unity gain (G = 1) with RF = 750 Ω and RL = 100 Ω, THS3125IDRG4 achieves a small-signal –3-dB bandwidth of 160 MHz under ±15-V supply conditions. At ±5 V, bandwidth is 138 MHz. This is measured with standard current feedback configuration (feedback resistor from output to inverting input); bandwidth scales inversely with closed-loop gain setting. THS3125IDRG4 maintains flat group delay and low phase error across this range, making it suitable for wideband IF and baseband applications.

Can THS3125IDRG4 drive 75-Ω video loads directly?

Yes, THS3125IDRG4 is explicitly characterized for 75-Ω video loads: it achieves 0.01% differential gain error and 0.011° differential phase error driving 75-Ω serially terminated lines at NTSC/PAL frequencies. For optimal performance, use G = 2 with RF = 470 Ω and match source impedance to 75 Ω. Output swing reaches 26 VPP into 50 Ω, exceeding SMPTE 259M requirements. THS3125IDRG4 eliminates need for external emitter followers or transformer coupling in professional video infrastructure.