LT1678/LT1679
Dual/Quad Low Noise,
Rail-to-Rail, Precision Op Amps
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FEATURES
DESCRIPTIO
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The LT ®1678/LT1679 are dual/quad rail-to-rail op amps
offering both low noise and precision: 3.9nV/√Hz wideband
noise, 1/f corner frequency of 4Hz and 90nV peak-to-peak
0.1Hz to 10Hz noise are combined with outstanding
precision: 100µV maximum offset voltage, greater than
100dB common mode and power supply rejection and
20MHz gain bandwidth product. The LT1678/LT1679 bring
precision as well as low noise to single supply applications as
low as 3V. The input range exceeds the power supply by
100mV with no phase inversion while the output can swing
to within 170mV of either rail.
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Rail-to-Rail Input and Output
100% Tested Low Voltage Noise:
3.9nV/√Hz Typ at 1kHz
5.5nV/√Hz Max at 1kHz
Single Supply Operation from 2.7V to 36V
Offset Voltage: 100µV Max
Low Input Bias Current: 20nA Max
High AVOL: 3V/µV Min, RL = 10k
High CMRR: 100dB Min
High PSRR: 106dB Min
Gain Bandwidth Product: 20MHz
Operating Temperature Range: – 40°C to 85°C
Matching Specifications
No Phase Inversion
8-Lead SO and 14-Lead SO Packages
The LT1678/LT1679 are offered in the SO-8 and SO-14
packages. A full set of matching specifications are also
provided, facilitating their use in matching dependent applications such as a two op amp instrumentation amplifier
design. The LT1678/LT1679 are specified for supply voltages of ±15V, single 5V as well as single 3V. For a single
amplifier with similiar performance, see the LT1677 data
sheet.
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APPLICATIO S
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Strain Gauge Amplifiers
Portable Microphones
Battery-Powered Rail-to-Rail Instrumentation
Low Noise Signal Processing
Microvolt Accuracy Threshold Detection
Infrared Detectors
, LTC and LT are registered trademarks of Linear Technology Corporation.
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TYPICAL APPLICATIO
Instrumentation Amplifier with Shield Driver
2
0.1Hz to 10Hz Voltage Noise
+
1
1/4
LT1679
1k
VS = ±2.5V
–
RF
3.4k
+
8
10
–
+
–
15V
5
GUARD
INPUT
30k
9
1/4
LT1679
RG
100Ω
6
4
+
1/4
LT1679
–
RG
100Ω
11
–15V
7
OUTPUT
30k
VOLTAGE NOISE (50nV/DIV)
3
GUARD
GAIN = 1000
13
12
–
1/4
LT1679
+
14
0
RF
3.4k
16789 TA01
2
4
6
TIME (sec)
8
10
16789 TA01b
1k
sn16789 16789fs
1
