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.