OPA657 Datasheet, PDF (1/20 Pages) Texas Instruments – 1.6GHz, Low-Noise, FET-Input OPERATIONAL AMPLIFIER

OPA657
OPA657
SBOS197B – DECEMBER 2001 – REVISED MAY 2004
1.6GHz, Low-Noise, FET-Input
OPERATIONAL AMPLIFIER
FEATURES
q HIGH GAIN BANDWIDTH PRODUCT: 1.6GHz
q HIGH BANDWIDTH 275MHz (G = +10)
q LOW INPUT OFFSET VOLTAGE: ±0.25mV
q LOW INPUT BIAS CURRENT: 2pA
q LOW INPUT VOLTAGE NOISE: 4.8nV/ Hz
q HIGH OUTPUT CURRENT: 70mA
q FAST OVERDRIVE RECOVERY
APPLICATIONS
q WIDEBAND PHOTODIODE AMPLIFIER
q WAFER SCANNING EQUIPMENT
q ADC INPUT AMPLIFIER
q TEST AND MEASUREMENT FRONT END
q HIGH GAIN PRECISION AMPLIFIER
DESCRIPTION
The OPA657 combines a high gain bandwidth, low distor-tion,
voltage-feedback op amp with a low voltage noise JFET-input
stage to offer a very high dynamic range amplifier for high
precision ADC (Analog-to-Digital Converter) driving or wideband
transimpedance applications. Photodiode applications will see
improved noise and bandwidth using this decompensated,
high gain bandwidth amplifier.
Very low level signals can be significantly amplified in a single
OPA657 gain stage with exceptional bandwidth and accuracy.
Having a high 1.6GHz gain bandwidth product will give >
10MHz signal bandwidths up to gains of 160V/V (44dB). The
very low input bias current and capacitance will support this
performance even for relatively high source impedances.
Broadband photodetector applications will benefit from the low
voltage noise JFET inputs for the OPA657. The JFET input
contributes virtually no current noise while for broadband
applications, a low voltage noise is also required. The low
4.8nV/ Hz input voltage noise will provide exceptional input
sensitivity for higher bandwidth applications. The example
shown below will give a total equivalent input noise current of
1.8pA/ Hz over a 10MHz bandwidth.
200kΩ TRANSIMPEDANCE BANDWIDTH
116
10MHz Bandwidth
106
96
86
RELATED OPERATIONAL AMPLIFIER PRODUCTS
SLEW VOLTAGE
V_S BW RATE NOISE
DEVICE (V) (MHz) (V/µS) (nV/√HZ) AMPLIFIER DESCRIPTION
OPA355 +5 200 300
OPA655 ±5 400 290
OPA656 ±5 500 170
OPA627 ±15 16 55
THS4601 ±15 180 100
5.80 Unity-Gain Stable CMOS
6
Unity-Gain Stable FET-Input
7
Unity-Gain Stable FET-Input
4.5 Unity-Gain Stable FET-Input
5.4 Unity-Gain Stable FET-Input
76
0.1pF
66
100kHz
1MHz
Frequency
10MHz
50MHz
200kΩ
λ
OPA657
V_O
(12pF)
–V_b
Wideband Photodiode Transimpedance Amplifier
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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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