OPA847IDRG4 Datasheet, PDF (1/30 Pages) Texas Instruments – Wideband, Ultra-Low Noise, Voltage-Feedback OPERATIONAL AMPLIFIER with Shutdown

OPA847
OPA847
www.ti.com
SBOS251E – JULY 2002 – REVISED DECEMBER 2008
Wideband, Ultra-Low Noise, Voltage-Feedback
OPERATIONAL AMPLIFIER with Shutdown
FEATURES
q HIGH GAIN BANDWIDTH: 3.9GHz
q LOW INPUT VOLTAGE NOISE: 0.85nV/_√Hz
q VERY LOW DISTORTION: –105dBc (5MHz)
q HIGH SLEW RATE: 950V/µs
q HIGH DC ACCURACY: V_IO < ±100µV
q LOW SUPPLY CURRENT: 18.1mA
q LOW SHUTDOWN POWER: 2mW
q STABLE FOR GAINS ≥ 12
APPLICATIONS
q HIGH DYNAMIC RANGE ADC PREAMPS
q LOW NOISE, WIDEBAND, TRANSIMPEDANCE
AMPLIFIERS
q WIDEBAND, HIGH GAIN AMPLIFIERS
q LOW NOISE DIFFERENTIAL RECEIVERS
q ULTRASOUND CHANNEL AMPLIFIERS
q IMPROVED UPGRADE FOR THE OPA687,
CLC425, AND LMH6624
50Ω Source
1:2
< 5.1dB
Noise
Figure
100Ω
39pF
39pF
100Ω
+5V
OPA847
1.7pF
–5V
850Ω
850Ω
+5V
1.7pF
OPA847
0.001µF 20Ω
+5V
INP
2kΩ
100pF
V_CM
ADS5500
14-Bit
0.1µF
125MSPS
2kΩ
0.001µF 20Ω
INN
100pF
–5V
24.6dB Gain
Ultra-High Dynamic Range
Differential ADC Driver
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 op-
tional 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 discon-
nected to ensure normal amplifier operation when no power-
down 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 opti-
mized 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 Con-
verter (ADC) interface application, shown below, can deliver
one of the highest dynamic-range interfaces available.
OPA847 RELATED PRODUCTS
SINGLES
OPA842
OPA843
OPA846
INPUT NOISE
VOLTAGE (nV/√Hz )
2.6
2.0
1.2
GAIN BANDWIDTH
PRODUCT (MHz)
200
800
1750
DIFFERENTIAL OPA847 DRIVER DISTORTION
–70
2V_PP, at converter input.
–75
–80
–85
–90
–95
–100
2nd-Harmonic
3rd-Harmonic
–105
–110
10
20
30
Frequency (MHz)
40 50
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
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