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Product details

Parameters

Architecture Current FB Number of channels (#) 1 Total supply voltage (Min) (+5V=5, +/-5V=10) 14 Total supply voltage (Max) (+5V=5, +/-5V=10) 32 GBW (Typ) (MHz) 900 BW @ Acl (MHz) 900 Acl, min spec gain (V/V) 1 Slew rate (Typ) (V/us) 8000 Vn at flatband (Typ) (nV/rtHz) 1.85 Vn at 1 kHz (Typ) (nV/rtHz) 3 Iq per channel (Typ) (mA) 17.1 Vos (offset voltage @ 25 C) (Max) (mV) 2 Rail-to-rail No Features Shutdown Rating Catalog Operating temperature range (C) -40 to 85 CMRR (Typ) (dB) 75 Input bias current (Max) (pA) 5000000 Offset drift (Typ) (uV/C) 3 Output current (Typ) (mA) 420 2nd harmonic (dBc) 76 3rd harmonic (dBc) 69 @ MHz 50 open-in-new Find other High-speed op amps (GBW>=50MHz)

Package | Pins | Size

HSOIC (DDA) 8 19 mm² 4.9 x 3.9 VQFN (RGT) 16 9 mm² 3 x 3 open-in-new Find other High-speed op amps (GBW>=50MHz)

Features

  • Bandwidth:
    • 900 MHz (VO = 2 VPP, AV = 5 V/V)
    • 320 MHz (VO = 10 VPP, AV = 5 V/V)
  • Slew Rate: 8000 V/µs (VO = 20 VPP)
  • Input Voltage Noise: 1.7 nV/√Hz
  • Bipolar Supply Range: ±7 V to ±16 V
  • Single-Supply Range: 14 V to 32 V
  • Output Swing: 28 VPP (±16-V Supplies, 100-Ω Load)
  • Linear Output Current: ±420 mA (Typical)
  • 16.8-mA Trimmed Supply Current (Low Temperature Coefficient)
  • HD2 and HD3: Less Than –75 dBc (50 MHz, VO = 10 VPP, 100-Ω Load)
  • Rise and Fall Time: 1.3 ns (10-V Step)
  • Overshoot: 1.5% (10-V Step, AV = 5 V/V)
  • Current Limit and Thermal Shutdown Protection
  • Power Down Feature

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open-in-new Find other High-speed op amps (GBW>=50MHz)

Description

The THS3491 current feedback amplifier (CFA) provides a new level of performance for applications requiring the lowest distortion at high output power levels from DC through values greater than 100 MHz at 100-Ω loads. Although specified at a gain of 5 V/V, this current feedback design holds near constant bandwidth and distortion over a wide range of gains.

The 8000 V/µs of slew rate delivers an output of 10 VPP into demanding loads with low distortion through 100 MHz. The 900-MHz, small-signal bandwidth delivers a low overshoot of less than 1.5% for a 10-V step, and rise and fall times of less than 1.3 ns. Peak output current drive values greater than 500 mA enable driving heavy capacitive loads with fast signals.

New designs benefit from the lowest distortion using the VQFN-16 (RGT) package, whereas the 8-pin HSOIC (DDA) package (with PowerPAD™) upgrades existing THS3091 or THS3095 designs. Lower output headroom for the THS3491 provides more output swing on the same ±15-V supplies versus legacy THS3091 or THS3095 options.

open-in-new Find other High-speed op amps (GBW>=50MHz)
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Technical documentation

= Top documentation for this product selected by TI
No results found. Please clear your search and try again. View all 9
Type Title Date
* Datasheet THS3491 900-MHz, 500-mA High-Power Output Current Feedback Amplifier datasheet (Rev. B) Jul. 03, 2018
Technical articles 3 common questions when designing with high-speed amplifiers Jul. 17, 2020
Technical articles How to reduce distortion in high-voltage, high-frequency signal generation for AWGs Oct. 30, 2018
Technical articles What are the advantages of using JFET-input amplifiers in high-speed applications? Jun. 18, 2018
Technical articles Unique active mux capability combines buffer and switch into one solution Oct. 10, 2017
User guide THS3491RGT EVM User's Guide Aug. 09, 2017
User guide THS3491DDA EVM User's Guide Aug. 08, 2017
Application note Load Sharing Concepts: Implementation for Large-Signal Applications Oct. 05, 2011
Application note Noise Analysis for High Speed Op Amps (Rev. A) Jan. 17, 2005

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Hardware development

EVALUATION BOARD Download
249
Description
The THS3491DDA evaluation module (EVM) is used to evaluate the THS3491 device, which is a highspeed, high-voltage and low-distortion current-feedback amplifier in an 8-pin DDA package. The EVM is designed to quickly and easily demonstrate the functionality and performance of THS3491 in a gain of 5 (...)
Features
  • Configured for split-supply operation and easily modified for single supply
  • Designed for single-ended 50-Ω input and output connection
  • Configured for non-inverting gain of 5 V/V configuration and easily modified for inverting gain configuration
  • Simple interface to the inputs and outputs through the SMA (...)
EVALUATION BOARD Download
249
Description
The THS3491RGT evaluation module (EVM) is used to evaluate the THS3491 device, which is a high speed, high-voltage and low-distortion current-feedback amplifier in an 16-pin RGT package. The EVM is designed to quickly and easily demonstrate the functionality and performance of THS3491 in a gain of 5 (...)
Features
  • Configured for split-supply operation and easily modified for single supply
  • Designed for single-ended 50-Ω input and output connection 
  • Configured for non-inverting gain of 5 V/V configuration and easily modified for inverting gain configuration 
  • Simple interface to the inputs and outputs through the (...)

Design tools & simulation

SIMULATION MODEL Download
SBOMAI4A.TSC (1189 KB) - TINA-TI Reference Design
SIMULATION MODEL Download
SBOMAI5A.ZIP (11 KB) - TINA-TI Spice Model
SIMULATION MODEL Download
SBOMAN3.TSC (344 KB) - TINA-TI Reference Design
SIMULATION MODEL Download
SBOMAN4.ZIP (11 KB) - TINA-TI Spice Model
SIMULATION TOOL Download
PSpice® for TI design and simulation tool
PSPICE-FOR-TI — PSpice® for TI is a design and simulation environment that helps evaluate functionality of analog circuits. This full-featured, design and simulation suite uses an analog analysis engine from Cadence®. Available at no cost, PSpice for TI includes one of the largest model libraries in the (...)
Features
  • Leverages Cadence PSpice Technology
  • Preinstalled library with a suite of digital models to enable worst-case timing analysis
  • Dynamic updates ensure you have access to most current device models
  • Optimized for simulation speed without loss of accuracy
  • Supports simultaneous analysis of multiple products
  • (...)
SIMULATION TOOL Download
SPICE-based analog simulation program
TINA-TI TINA-TI provides all the conventional DC, transient and frequency domain analysis of SPICE and much more. TINA has extensive post-processing capability that allows you to format results the way you want them. Virtual instruments allow you to select input waveforms and probe circuit nodes voltages (...)
CALCULATION TOOL Download
Analog engineer's calculator
ANALOG-ENGINEER-CALC — The Analog Engineer’s Calculator is designed to speed up many of the repetitive calculations that analog circuit design engineers use on a regular basis. This PC-based tool provides a graphical interface with a list of various common calculations ranging from setting op-amp gain with feedback (...)
Features
  • Expedites circuit design with analog-to-digital converters (ADCs) and digital-to-analog converters (DACs)
    • Noise calculations
    • Common unit translation
  • Solves common amplifier circuit design problems
    • Gain selections using standard resistors
    • Filter configurations
    • Total noise for common amplifier configurations
  • (...)
CALCULATION TOOL Download
Voltage Divider Determines A Set of Resistors for a Voltage Divider
VOLT-DIVIDER-CALC VOLT-DIVIDER-CALC quickly determines a set of resistors for a voltage divider. This KnowledgeBase Javascript utility can be used to find a set of resistors for a voltage divider to achieve the desired output voltage. This calculator can also be used to design non-inverting attentuation circuits.

(...)

Reference designs

REFERENCE DESIGNS Download
100-MHz, 1 A Output current driver reference design for high capacitive load applications
TIDA-060002 — This TI Design uses the THS3491 high-speed, high-voltage current feedback amplifier to demonstrate an output current drive capability of greater than 1 A into a low resistive or high capacitive load while maintaining a large signal bandwidth of 100 MHz at 20 VPP. The high output current drive is (...)
document-generic Schematic

CAD/CAE symbols

Package Pins Download
SO PowerPAD (DDA) 8 View options
VQFN (RGT) 16 View options

Ordering & quality

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  • REACH
  • Device marking
  • Lead finish/Ball material
  • MSL rating/Peak reflow
  • MTBF/FIT estimates
  • Material content
  • Qualification summary
  • Ongoing reliability monitoring

Support & training

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