LTC6268/LTC6269
500MHz Ultra-Low Bias
Current FET Input Op Amp
FEATURES
DESCRIPTION
TheLTC®6268/LTC6269isasingle/dual500MHzFET-input
operationalamplifierwithextremelylowinputbiascurrent
and low input capacitance. It also features low input-
referred current noise and voltage noise making it an ideal
choice for high speed transimpedance amplifiers, CCD
output buffers, and high-impedance sensor amplifiers.
Its low distortion makes the LTC6268/LTC6269 an ideal
amplifier for driving SAR ADCs.
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Gain Bandwidth Product: 500MHz
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–3dB Bandwidth (A = 1): 350MHz
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Low Input Bias Current:
3fA Typ. Room Temperature
4pA Max at 125°C
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Current Noise (100kHz): 5.5fA/√Hz
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Voltage Noise (1MHz): 4.3nV/√Hz
Extremely Low C 450fF
Rail-to-Rail Output
Slew Rate: 400V/µs
Supply Range: 3.1V to 5.25V
Quiescent Current: 16.5mA
Harmonic Distortion (2V ):
–100dB at 1MHz
–80dB at 10MHz
Operating Temp Range: –40°C to 125°C
Single in 8-Lead SO-8, 6-Lead TSOT-23 Packages
Dualin8-LeadMS8, 3mm ×3mm10-LeadDFN10 Packages
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IN
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Itoperateson3.1Vto5.25Vsupplyandconsumes16.5mA
per amplifier. A shutdown feature can be used to lower
power consumption when the amplifier is not in use.
TheLTC6268singleopampisavailablein8-leadSOICand
6-lead SOT-23 packages. The SOIC package includes two
unconnected pins which can beusedto createan input pin
guard ring to protect against board leakage currents. The
LTC6269 dual op amp is available in 8-lead MSOP with
exposed pad and 3mm × 3mm 10-lead DFN packages.
They are fully specified over the –40°C to 85°C and the
–40°C to 125°C temperature ranges.
P-P
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APPLICATIONS
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
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Trans-Impedance Amplifiers
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ADC Drivers
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CCD Output Buffer
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Photomultiplier Tube Post-Amplifier
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Low I
Circuits
BIAS
20kΩ TIA Frequency Response
TYPICAL APPLICATION
100
20kΩ Gain 65MHz Trans-Impedance Amplifier
90
80
70
60
50
40
PARASITIC
FEEDBACK C
20kΩ*
2.5V
2.5V
PD
–
V
OUT
= –I • 20k
PD
I
PD
LTC6268
BW = 65MHz
+
–2.5V
6268 TA01
0.01
0.1
1
10
100
1000
PD = OSI OPTOELECTRONICS, FCI-125G-006
*TWO 40.2kΩ 0603 PACKAGE RESISTORS IN PARALLEL
FREQUENCY (MHz)
6268 TA02
62689f
1
For more information www.linear.com/LTC6268