Texas Instruments THS3122IDDARG3

Overview

THS3122IDDARG3 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 amplification of fast, heavy-loaded signals such as serially terminated video lines or piezoelectric actuator drivers.

For engineers reviewing the THS3122IDDARG3 datasheet, THS3122IDDARG3 pinout, THS3122IDDARG3 application, or THS3122IDDARG3 equivalent, key selection considerations include its SOIC-14 package with PowerPAD thermal enhancement, dual-channel independent operation, ±5-V to ±15-V dual-supply support, and absence of shutdown functionality (distinguishing it from THS3125 variants).

Technical Context

The THS3122IDDARG3 implements a current feedback architecture with high-impedance noninverting inputs and low-impedance inverting inputs, enabling stable gain-setting via feedback resistor networks without bandwidth degradation typical of voltage-feedback op-amps. Its transimpedance gain stage drives a Class-AB output stage capable of sourcing/sinking ±450 mA into 50-Ω loads.

It operates over –40°C to +85°C industrial temperature range with 7.2–10.5 mA per channel quiescent current (depending on supply), 2.9-pA/√Hz and 10.8-pA/√Hz input current noise at inverting/noninverting inputs respectively, and maintains <0.01% differential gain error driving four 75-Ω video lines.

Key Specifications

Pinout & Package

THS3122IDDARG3 is housed in a 14-pin SOIC (D) package with thermally enhanced PowerPAD on the underside, requiring PCB copper pour connection for optimal thermal performance. Pin 1 is top-left corner (notch-mark side), with pins numbered counter-clockwise.

Key Features

Applications

Equivalent & Alternatives

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

Compared with THS3122CD, THS3122IDDARG3 offers superior thermal performance and industrial temperature rating; compared with THS3125ID, it eliminates shutdown complexity while maximizing output stage reliability under continuous high-current load.

Availability

THS3122IDDARG3 is available at Aetrix Electronics and suitable for video distribution, industrial instrumentation, and high-current line driver applications requiring stable component supply, long-term manufacturability, and guaranteed industrial-temperature operation.

Supply support for THS3122IDDARG3 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 for industrial, automotive, and communications markets.

The THS312x family was designed specifically for high-fidelity, high-output-current analog signal conditioning - targeting broadcast video infrastructure, precision test equipment, and high-speed actuator control where low noise, wide bandwidth, and robust drive capability are critical.

FAQ

What is the maximum continuous output current specification for THS3122IDDARG3?

The THS3122IDDARG3 is rated for ±450 mA continuous output current per channel into resistive loads. This is validated under recommended operating conditions (±5 V to ±15 V supplies, TA ≤ +85°C) with proper thermal management using the PowerPAD. Absolute maximum rating is ±550 mA, but sustained operation above ±450 mA requires careful thermal design to avoid junction temperature exceedance.

Does THS3122IDDARG3 support single-supply operation?

No, THS3122IDDARG3 is specified exclusively for dual-supply operation from ±5 V to ±15 V. It does not support true single-supply configurations because its input common-mode range extends only to ±2.5 V (at ±5 V) or ±12.5 V (at ±15 V), and its output swing is symmetrical about ground. Attempting single-supply use will result in clipping and instability.

What is the purpose of the REF and SHUTDOWN pins on THS3122IDDARG3?

On THS3122IDDARG3, the REF and SHUTDOWN pins are non-functional - they are reserved for the THS3125 variant. The THS3122IDDARG3 has no shutdown capability and no reference voltage function. These pins (6 and 9) are internally disconnected; they may be left floating or tied to ground for mechanical stability, but must not be driven.

How does the PowerPAD on THS3122IDDARG3 improve thermal performance?

The PowerPAD on THS3122IDDARG3 reduces thermal resistance from junction to ambient to 66.6°C/W (vs. 95°C/W for SOIC-8). When soldered to a minimum 1-in² copper pour connected to internal ground planes, it dissipates heat directly from the die backside, allowing the THS3122IDDARG3 to sustain ±450 mA output continuously at +85°C ambient without derating - critical for industrial line drivers and video amplifiers.

Can THS3122IDDARG3 replace THS3125ID in an existing design?

THS3122IDDARG3 can replace THS3125ID only if shutdown functionality is unused and REF/SHUTDOWN pins are left unconnected. Electrically, both share identical AC/DC performance, bandwidth, noise, and drive capability. However, THS3122IDDARG3 lacks the 370-µA shutdown mode - so systems relying on dynamic power gating will require redesign or external control logic to maintain always-on operation.