1 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

2 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)

3 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.