Texas Instruments THS3120IDGN

Overview

THS3120IDGN from Texas Instruments is a low-noise, high-output-current, current-feedback operational amplifier in an MSOP-8 PowerPAD™ package, featuring 1700 V/μs slew rate (G=2, RL=50 Ω), 120 MHz small-signal bandwidth, ±15 V supply operation, and integrated power-down functionality. It drives multiple 75-Ω video loads with <0.007% differential gain error and <0.022° differential phase error-enabling precision analog video distribution in broadcast and professional AV equipment.

For engineers reviewing the THS3120IDGN datasheet, THS3120IDGN pinout, THS3120IDGN application, or THS3120IDGN equivalent, this page delivers verified electrical specs, thermal-aware package details, real-world video distortion performance, and validated alternatives for high-current, wide-bandwidth op-amp selection in demanding analog signal paths.

Technical Context

The THS3120IDGN employs a current-feedback architecture optimized for high-speed, high-fidelity signal amplification with minimal settling time (11 ns to 0.1%) and ultra-low harmonic distortion (–51 dBc 2nd harmonic at 10 MHz). Its transimpedance gain of 1.9 MΩ and 2.5 nV/√Hz input voltage noise support precision DC-coupled and AC-coupled video chain designs.

Power-down control via the PD pin reduces quiescent current from 7 mA to ≤500 μA while maintaining defined REF pin voltage range (VS– to VS+ – 4 V); turn-on/turn-off delays are 4 μs and 6 μs respectively. The MSOP-8 PowerPAD™ package requires thermal connection to PCB copper for reliable 685 mW power dissipation at TA = +85°C.

Key Specifications

Pinout & Package

THS3120IDGN uses an 8-pin MSOP PowerPAD™ package with exposed thermal pad electrically isolated from all pins. The PowerPAD must be soldered to a dedicated PCB copper pour for thermal management and optimal 685 mW power dissipation at +85°C ambient.

Key Features

Applications

Equivalent & Alternatives

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

Compared with THS3120IDGN, THS3121IDGN removes power-down capability but retains identical video performance and thermal design, while LMH6723MA/NOPB trades lower cost and wider availability for reduced slew rate, higher noise, and no broadcast-grade video characterization.

Availability

THS3120IDGN is available at Aetrix Electronics and suitable for professional video distribution, broadcast camera signal chains, industrial vision systems, and high-speed pin driver applications requiring stable component supply, guaranteed industrial temperature range (–40°C to +85°C), and TI-qualified reliability.

Supply support for THS3120IDGN 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 digital signal technologies, with decades of expertise in high-performance op-amps and video signal conditioning ICs.

The THS3120IDGN belongs to TI's high-speed current-feedback op-amp product line, engineered specifically for broadcast-quality video distribution, high-current analog output stages, and precision wideband amplification in industrial and professional AV systems.

FAQ

What is the maximum number of 75-Ω video loads the THS3120IDGN can drive while maintaining broadcast video specifications?

The THS3120IDGN maintains <0.007% differential gain and <0.022° differential phase error across up to eight 150-Ω loads (equivalent to four 75-Ω loads in parallel) under standard test conditions (G = 2, RF = 649 Ω, VS = ±15 V). Real-world 75-Ω distribution typically supports four simultaneous outputs with full SMPTE RP 168 compliance; additional loads require verification of gain flatness and phase shift at system level. THS3120IDGN's ±475 mA output current provides margin for longer cable runs or imperfect terminations.

How does the THS3120IDGN's power-down feature affect its output behavior and timing during enable/disable transitions?

When the PD pin is driven ≥REF + 2 V, the THS3120IDGN enters power-down mode with output placed in high-impedance state and quiescent current reduced to ≤500 μA. Turn-on delay is 4 μs (to 90% of final output), and turn-off delay is 6 μs (to 10% of final output). During transition, the output remains well-behaved with no overshoot or latch-up. The REF pin must be biased within VS– to (VS+ – 4 V); if left floating, the device defaults to enabled state. THS3120IDGN's internal PD pin bias current is 11 μA, limiting practical pull-up resistor values to ≤220 kΩ for 3.3-V logic compatibility.

Can the THS3120IDGN operate from a single +10 V to +30 V supply, and what are the implications for output swing and thermal design?

Yes, the THS3120IDGN supports single-supply operation from +10 V to +30 V (with VS– tied to ground), per Absolute Maximum Ratings and Recommended Operating Conditions. At +30 V, output swing is ±13.5 V into 50 Ω (i.e., 27 VPP), but thermal dissipation rises significantly: at TA = +85°C, maximum continuous power drops to 685 mW in the MSOP-8 PowerPAD™ package. To sustain full output swing, the PowerPAD must be soldered to ≥3″ × 3″ 2-oz copper; derating is required above +24 V unless forced-air cooling is applied. THS3120IDGN's input common-mode range extends to within 2.2 V of rails, enabling DC-coupled single-supply video interfaces.

What layout practices are essential to achieve the specified 120 MHz bandwidth and low distortion performance of the THS3120IDGN?

To achieve 120 MHz bandwidth and <0.007% differential gain, THS3120IDGN requires strict RF layout: (1) Place 0.1 μF ceramic decoupling caps <2 mm from VS+ and VS− pins; (2) Route VIN− and VIN+ with matched length and 50-Ω controlled impedance; (3) Connect PowerPAD to solid thermal plane using ≥4 thermal vias (0.3 mm diameter); (4) Keep feedback resistor (RF = 649 Ω) and gain-setting network directly adjacent to pins 2/3/7 with shortest possible traces; (5) Avoid stubs on VOUT - route directly to connector or load with 75-Ω microstrip. Ground plane must be uninterrupted beneath amplifier footprint to suppress parasitic inductance.

How does the THS3120IDGN's current-feedback architecture differ from conventional voltage-feedback op-amps in terms of stability and compensation requirements?

Unlike voltage-feedback op-amps, the THS3120IDGN's current-feedback topology has gain-bandwidth independence: bandwidth remains ~120 MHz regardless of closed-loop gain (G = 1 to 10), provided RF is scaled per datasheet table (e.g., 649 Ω at G = 2, 301 Ω at G = 10). Stability depends critically on feedback resistance - reducing RF below recommended values causes peaking and oscillation. Capacitive loads >10 pF require series isolation resistor (RISO) per Figure 8 (e.g., 20 Ω for 100 pF). THS3120IDGN does not use internal compensation; external RF and RISO set bandwidth and phase margin. This enables faster settling and higher slew rates than equivalently rated voltage-feedback amplifiers.