OPA657 Datasheet, PDF (1/37 Pages) Texas Instruments – 1.6GHz, Low-Noise, FET-Input OPERATIONAL AMPLIFIER

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OPA657
SBOS197F – DECEMBER 2001 – REVISED AUGUST 2015
OPA657 1.6-GHz, Low-Noise, FET-Input Operational Amplifier
1 Features
•1 High Gain Bandwidth Product: 1.6 GHz
• High Bandwidth 275 MHz (G = 10)
• Slew Rate 700 V/µs (G = 10, 1-V Step)
• Available in High Grade With Improved DC
Specifications
• Operating Temperature Range: –40°C to 85°C
• Low-Input Offset Voltage: ±250 µV
• Low-Input Bias Current: 2 pA
• Low-Input Voltage Noise: 4.8 nV/√Hz
• High-Output Current: 70 mA
• Fast Overdrive Recovery
2 Applications
• Wideband Photodiode Amplifier
• Wafer Scanning Equipment
• ADC Input Amplifier
• Test and Measurement Front End
• High Gain Precision Amplifier
• Optical Time Domain Reflectometry (OTDR)
3 Description
The OPA657 device combines a high-gain bandwidth,
low-distortion, voltage-feedback operational amplifier
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
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 1.6-GHz gain
bandwidth product gives greater than 10-MHz signal
bandwidths up to gains of 160 V/V (44 dB). The very
low input bias current and capacitance supports this
performance even for relatively high source
impedances.
Broadband photodetector applications 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 4.8 nV/√Hz input voltage
noise provides exceptional input sensitivity for higher
bandwidth applications. The example shown below
gives a total equivalent input noise current of 1.8
pA/√Hz over a 10-MHz bandwidth.
Frequency Response of 200-kΩ Transimpedance
Amplifier
116
10MHz Bandwidth
106
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
OPA657
SOT-23 (5)
SOIC (8)
2.90 mm × 1.60 mm
4.90 mm × 3.91 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Wideband Photodiode Transimpedance Amplifier
0.1pF
200kΩ
96
l
OPA657
V_O
(12pF)
86
76
-V_b
66
100k
1M
10M
50M
Frequency (Hz)
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.