Texas Instruments THS3115CD

Overview

THS3115CD from Texas Instruments is a dual-channel, low-noise, high-speed current-feedback amplifier in SOIC-8 package, delivering 110-MHz bandwidth (G=1, ±15 V), 1550-V/µs slew rate (G=2), and 150-mA output drive into 100 Ω. It operates from ±5 V to ±15 V supplies and features low-power shutdown mode with 300-µA quiescent current per channel - ideal for video distribution and piezo driver applications requiring wide output swing and minimal distortion.

For engineers reviewing the THS3115CD datasheet, THS3115CD pinout, THS3115CD application, or THS3115CD equivalent, key selection criteria include its current-feedback architecture, shutdown control interface (REF/SHUTDOWN pins), 2.2-nV/√Hz voltage noise at 10 kHz, –78-dBc THD at 1 MHz, and compatibility with 50-Ω source/load systems in high-fidelity signal paths.

Technical Context

The THS3115CD uses a current-feedback topology with transimpedance gain stage, enabling high slew rate and bandwidth independent of closed-loop gain. Its feedback network relies on precise RF/RG resistor matching (e.g., 750 Ω for G=2) to minimize peaking and ensure stability across ±5 V to ±15 V operation.

It integrates dedicated REF and SHUTDOWN terminals for threshold-controlled power management: REF sets reference level (VCC– to VCC+–4 V), while SHUTDOWN enables/disables the channel when driven above REF+2 V (disable) or below REF+0.8 V (enable), with 200 ns disable and 300 ns enable times at ±15 V.

Key Specifications

Pinout & Package

THS3115CD is housed in an 8-pin SOIC (D) package with standard pinout and exposed thermal pad (PowerPAD™ not present in SOIC-8 variant per TI SLOS385C Rev. September 2010).

Key Features

Applications

Equivalent & Alternatives

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

Compared with THS3112CD, THS3115CD adds programmable shutdown with 300-µA quiescent current but retains identical AC performance; versus THS3095DR, it trades bandwidth and slew rate for dual-channel integration and lower power, making it optimal for space-constrained, battery-aware video and actuator systems.

Availability

THS3115CD is available at Aetrix Electronics and suitable for video distribution, piezo actuator control, and high-speed pulse amplification requiring stable component supply, long-term production continuity, and TI-qualified industrial temperature grade (0°C to +70°C).

Supply support for THS3115CD 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 50 years of innovation in high-performance signal chain solutions.

The THS3115CD belongs to TI's high-speed current-feedback amplifier product line, engineered for applications demanding wide bandwidth, high output current, and low distortion - especially in video, test equipment, and precision motion control.

FAQ

What is the maximum safe supply voltage for THS3115CD?

The absolute maximum supply voltage for THS3115CD is ±16.5 V (33 V total), but TI specifies recommended operation from ±5 V to ±15 V. Exceeding ±15 V risks exceeding junction temperature limits under load and may degrade long-term reliability. The THS3115CD datasheet confirms 150°C max junction temperature and thermal resistance (qJA = 95°C/W for SOIC-8), so sustained operation at ±15 V requires adequate PCB copper pour and airflow.

Does THS3115CD support single-supply operation?

Yes, THS3115CD supports single-supply operation from 10 V to 30 V. When used in single-supply mode, the noninverting inputs must be biased at mid-supply (e.g., VS/2) using precision resistive dividers or dedicated reference ICs, and output swing is centered around that bias point. Figure 41 in the THS3115CD datasheet shows validated inverting and noninverting configurations for this use case.

How does the REF pin function in THS3115CD?

The REF pin in THS3115CD sets the reference voltage for the internal shutdown comparator. It accepts any voltage from VCC– to VCC+–4 V. When left unconnected, REF defaults to VCC–, causing SHUTDOWN to remain below the enable threshold (REF+0.8 V) and keeping the device active. To implement controlled shutdown, REF is typically tied to a stable reference or mid-supply node, allowing SHUTDOWN to toggle relative to that baseline.

Can THS3115CD drive 50-Ω loads directly?

Yes, THS3115CD is explicitly characterized and optimized for 50-Ω source and load impedances. Its output stage delivers 150 mA into 100 Ω and maintains stability with 750-Ω feedback resistors in G=2 configurations. For direct 50-Ω termination, TI recommends using the inverting configuration shown in Figure 40 of the THS3115CD datasheet with matched 50-Ω series and shunt resistors to preserve bandwidth and minimize reflections.

What is the typical enable time for THS3115CD shutdown mode?

The typical enable time for THS3115CD is 300 ns at ±15 V supply, defined as the time from SHUTDOWN pin crossing the enable threshold (REF+0.8 V) to supply current reaching 50% of its active value. This fast wake-up supports burst-mode operation in power-sensitive systems like portable ultrasound or battery-powered test gear, where rapid channel activation is critical after sleep intervals.