Texas Instruments THS3491 Current Feedback Amplifier (CFA)

Texas Instruments 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 100MHz at 100Ω loads. Although specified at a gain of 5V/V, this current feedback design holds near-constant bandwidth and distortion over a wide range of gains.

The 8000V/µs of slew rate for the Texas Instruments THS3491 delivers an output of 10VPP into demanding loads with low distortion through 100MHz. The 900MHz, small-signal bandwidth delivers a low overshoot of less than 1.5% for a 10V step and rise and fall times of less than 1.3ns. Peak output current drive values greater than 500mA enable driving heavy capacitive loads with fast signals.

Features

  • Bandwidth
    • 900MHz (VO = 2VPP, AV = 5V/V)
    • 320MHz (VO = 10VPP, AV = 5V/V)
  • 8000V/µs (VO = 20VPP) slew rate 
  • 1.7nV/√Hz input voltage noise 
  • ±7V to ±16V bipolar supply range 
  • 14V to 32V single-supply range 
  • 28VPP (±16V supplies, 100Ω load) output swing
  • ±420mA (typical) linear output current 
  • 16.8mA trimmed supply current (low-temperature coefficient)
  • HD2 and HD3 less than –75dBc (50MHz, VO = 10VPP, 100Ω load)
  • 1.3ns (10V step) rise and fall time 
  • 1.5% (10V step, AV = 5V/V) overshoot 
  • Current limit and thermal shutdown protection
  • Power down feature

Applications

  • High-voltage, arbitrary waveform generators
  • Pattern generators for LCD testers
  • Output drivers for LCR meters
  • Power FET drivers
  • High capacitive load piezo element drivers
  • VDSL line drivers
  • Pin-compatible upgrade to THS3095 (DDA)

Functional Block Diagram

Block Diagram - Texas Instruments THS3491 Current Feedback Amplifier (CFA)
Inilathala: 2018-06-06 | Na-update: 2023-02-13