FEATURES

HIGH GAIN BANDWIDTH: 3.9GHz

LOW INPUT VOLTAGE NOISE: 0.85nV/√Hz

VERY LOW DISTORTION: –105dBc (5MHz)

HIGH SLEW RATE: 950V/μs

HIGH DC ACCURACY: VIO < ±100μV

LOW SUPPLY CURRENT: 18.1mA

LOW SHUTDOWN POWER: 2mW

STABLE FOR GAINS ≥ 12

APPLICATIONS

HIGH DYNAMIC RANGE ADC PREAMPS

LOW NOISE, WIDEBAND, TRANSIMPEDANCE

AMPLIFIERS

WIDEBAND, HIGH GAIN AMPLIFIERS

LOW NOISE DIFFERENTIAL RECEIVERS

ULTRASOUND CHANNEL AMPLIFIERS

IMPROVED UPGRADE FOR THE OPA687,

CLC425, AND LMH6624

DESCRIPTION

The OPA847 combines very high gain bandwidth and large

signal performance with an ultra-low input noise voltage

(0.85nV/√Hz) while using only 18mA supply current. Where

power saving is critical, the OPA847 also includes an optional

power shutdown pin that, when pulled low, disables the

amplifier and decreases the supply current to < 1% of the

powered-up value. This optional feature may be left disconnected

to ensure normal amplifier operation when no powerdown

is required.

The combination of very low input voltage and current noise,

along with a 3.9GHz gain bandwidth product, make the

OPA847 an ideal amplifier for wideband transimpedance

applications. As a voltage gain stage, the OPA847 is optimized

for a flat frequency response at a gain of +20V/V and

is stable down to gains as low as +12V/V. New external

compensation techniques allow the OPA847 to be used at

any inverting gain with excellent frequency response control.

Using this technique in a differential Analog-to-Digital Converter

(ADC) interface application, shown below, can deliver

one of the highest dynamic-range interfaces available.