Texas Instruments THS3112IDDAR

Overview

THS3112IDDAR from Texas Instruments is a dual-channel, low-noise, high-speed current-feedback amplifier in SOIC-8 PowerPAD™ package, delivering 110-MHz bandwidth (G=1, ±15 V), 1550-V/µs slew rate (G=2), and 2.2-nV/√Hz voltage noise. It drives 100-Ω loads with ±12.5-V output swing and supports ±5 V to ±15 V dual supplies - ideal for video distribution amplifiers requiring wide bandwidth and low distortion.

For engineers reviewing the THS3112IDDAR datasheet, THS3112IDDAR pinout, THS3112IDDAR application, or THS3112IDDAR equivalent, key selection criteria include its current-feedback architecture, PowerPAD thermal performance, noninverting/inverting input current noise asymmetry (2.9 pA/√Hz vs. 10.8 pA/√Hz), and absence of shutdown functionality compared to THS3115.

Technical Context

The THS3112IDDAR employs a current-feedback topology with transimpedance gain stage, enabling high slew rate and bandwidth independent of closed-loop gain. Its input stage features matched high-impedance noninverting (+) and low-impedance inverting (–) inputs, with RI(IN+) = 1.5 MΩ and RI(IN–) = 15 Ω.

It operates without internal shutdown logic - unlike the pin-compatible THS3115 - and requires external feedback resistors (e.g., 750 Ω for G=2) to set bandwidth and stability. Thermal management relies on the exposed PowerPAD™ die attach pad, which must be soldered to a PCB copper plane per TI SLMA002 guidelines.

Key Specifications

Pinout & Package

THS3112IDDAR uses an 8-pin SOIC PowerPAD™ (DDA) package with thermally enhanced exposed die attach pad on underside. The PowerPAD™ must be soldered to a PCB thermal plane for junction temperature control; failure to do so risks exceeding +150°C max T_J.

Key Features

Applications

Equivalent & Alternatives

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

Compared with THS3112CD, THS3112IDDAR provides 41% higher thermal dissipation capability via PowerPAD™; compared with THS3115IDDA, it eliminates shutdown pin routing complexity but forfeits power-gating - making it optimal for always-on, thermally demanding video or driver applications.

Availability

THS3112IDDAR is available at Aetrix Electronics and suitable for video distribution, piezo sensor conditioning, and motor current sensing applications requiring stable component supply, consistent parametric performance, and long-term industrial availability.

Supply support for THS3112IDDAR 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 amplifier design.

The THS3112IDDAR belongs to TI's THS31xx current-feedback amplifier family, engineered specifically for wideband, high-output-current applications including video, test equipment, and precision actuator drivers.

FAQ

What is the maximum safe operating junction temperature for THS3112IDDAR?

The absolute maximum junction temperature for THS3112IDDAR is +150°C. To ensure reliability, thermal design must keep T_J ≤ +125°C under worst-case conditions. With its SOIC PowerPAD™ (DDA) package (θ_JA = 67°C/W), maintaining PCB copper area ≥ 250 mm² under the PowerPAD™ is essential - especially when delivering 150 mA continuously. THS3112IDDAR thermal performance is validated per JEDEC high-K test board standards.

Does THS3112IDDAR support single-supply operation?

Yes, THS3112IDDAR supports single-supply operation from 10 V to 30 V, as specified in the Recommended Operating Conditions table. Input and output must be biased at mid-supply (e.g., V_CC/2) using external resistive dividers or reference ICs to maximize output swing. Unlike dual-supply mode, single-supply use reduces available headroom by one rail - e.g., with +15 V supply, max output swing is ~0 V to ~13.3 V into 100 Ω. THS3112IDDAR does not integrate internal level-shifting circuitry.

How does THS3112IDDAR differ from THS3115 in pin compatibility and functionality?

THS3112IDDAR and THS3115IDDA share identical SOIC PowerPAD™ (DDA) packaging and pinout for pins 1–8, but THS3115 adds two dedicated pins: REF (pin 9) and SHUTDOWN (pin 10). THS3112IDDAR has no shutdown capability and omits those pins entirely. Functionally, THS3112IDDAR draws 4.9–7.5 mA per channel continuously, while THS3115IDDA reduces to 300 µA in shutdown - making THS3112IDDAR appropriate only for always-on applications where power gating is unnecessary.

What feedback resistor value is recommended for THS3112IDDAR at G=2?

For a noninverting gain of 2 V/V, TI recommends RF = 750 Ω and RG = 750 Ω for THS3112IDDAR, as documented in Table 1 of the SLOS385C datasheet. This combination delivers optimal bandwidth (110 MHz) with minimal peaking in the frequency response. Using lower RF values increases bandwidth but introduces instability risk; higher values reduce bandwidth and improve phase margin. THS3112IDDAR's current-feedback architecture makes gain setting resistor selection critical - unlike voltage-feedback op-amps, gain is determined by RF alone in inverting configurations.

Can THS3112IDDAR drive capacitive loads, and what compensation is required?

Yes, THS3112IDDAR can drive capacitive loads up to several hundred picofarads, but requires external compensation to maintain stability. TI recommends inserting a series isolation resistor (R_ISO) between the output and load - e.g., 5.11 Ω for 100-pF load, scaling to 20–50 Ω for >1000-pF loads. Alternatively, a ferrite bead with ~30-Ω impedance at 100 MHz may replace R_ISO. Uncompensated capacitive loading causes peaking or oscillation due to phase shift introduced by the load capacitance interacting with the amplifier's high-frequency output impedance.