LT1678/LT1679
Dual/Quad Low Noise,
Rail-to-Rail, Precision Op Amps
FEATURES
■
■
DESCRIPTIO
■
■
■
■
■
■
■
■
■
■
■
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 A
VOL
: 3V/µV Min, R
L
= 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 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.
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 appli-
cations such as a two op amp instrumentation amplifier
design. The LT1678/LT1679 are specified for supply volt-
ages of
±15V,
single 5V as well as single 3V. For a single
amplifier with similiar performance, see the LT1677 data
sheet.
, LTC and LT are registered trademarks of Linear Technology Corporation.
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
TYPICAL APPLICATIO
3
Instrumentation Amplifier with Shield Driver
+
1/4
LT1679
1
1k
R
F
3.4k
5
30k
2
–
GUARD
INPUT
+
–
GUARD
+
8
1/4
LT1679
10
R
G
100Ω
6
R
G
100Ω
+
–
4
1/4
LT1679
11
–15V
7
OUTPUT
30k
–
9
GAIN = 1000
13
VOLTAGE NOISE (50nV/DIV)
15V
–
1/4
LT1679
14
R
F
3.4k
16789 TA01
12
+
1k
U
0.1Hz to 10Hz Voltage Noise
V
S
=
±2.5V
0
2
4
6
TIME (sec)
8
10
16789 TA01b
U
U
sn16789 16789fs
1
LT1678/LT1679
ABSOLUTE
(Note 1)
AXI U
RATI GS
Lead Temperature (Soldering, 10 sec.)................. 300°C
Operating Temperature Range
(Note 4) ............................................. – 40°C to 85°C
Specified Temperature Range
(Note 5) ............................................. – 40°C to 85°C
Supply Voltage ......................................................
±18V
Input Voltages (Note 2) ............ 0.3V Beyond Either Rail
Differential Input Current (Note 2) .....................
±
25mA
Output Short-Circuit Duration (Note 3) ............ Indefinite
Storage Temperature Range ................. – 65°C to 150°C
PACKAGE/ORDER I FOR ATIO
TOP VIEW
OUT A 1
–IN A 2
+IN A 3
V
–
4
A
B
8 V
+
7 OUT B
6 –IN B
5 +IN B
ORDER PART
NUMBER
LT1678CS8
LT1678IS8
S8 PART MARKING
1678
1678I
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 150°C,
θ
JA
= 190°C/ W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
The
●
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
S
= 3V, V
CM
= V
O
= 1.7V; V
S
= 5V, V
CM
= V
O
= 2.5V unless
otherwise noted.
SYMBOL
V
OS
PARAMETER
Input Offset Voltage
CONDITIONS (Note 6)
(Note 11)
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
V
S
=5V, V
CM
= V
S
+ 0.1V
V
S
=5V, V
CM
= V
S
– 0.3V, 0°C
≤
T
A
≤
70°C
V
S
=5V, V
CM
= V
S
– 0.3V, – 40°C
≤
T
A
≤
85°C
V
S
=5V, V
CM
= – 0.1V
V
S
=5V, V
CM
= 0V, 0°C
≤
T
A
≤
70°C
V
S
=5V, V
CM
= 0V, – 40°C
≤
T
A
≤
85°C
∆V
OS
∆Temp
I
B
Average Input Offset Drift (Note 10)
Input Bias Current
(Note 11)
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
●
●
●
●
●
●
●
ELECTRICAL CHARACTERISTICS
V
S
= 5V, V
CM
= V
S
+ 0.1V
●
V
S
= 5V, V
CM
= V
S
– 0.3V, 0°C
≤
T
A
≤
70°C
V
S
= 5V, V
CM
= V
S
– 0.3V, – 40°C
≤
T
A
≤
85°C
●
V
S
= 5V, V
CM
= – 0.1V
V
S
= 5V, V
CM
= 0V, 0°C
≤
T
A
≤
70°C
V
S
= 5V, V
CM
= 0V, – 40°C
≤
T
A
≤
85°C
●
●
2
U
U
W
W W
U
W
TOP VIEW
OUT A 1
–IN A 2
+IN A 3
V
+
4
+IN B 5
–IN B 6
OUT B 7
B
C
A
D
14 OUT D
13 –IN D
12 +IN D
11 V
–
10 +IN C
9
8
–IN C
OUT C
ORDER PART
NUMBER
LT1679CS
LT1679IS
S PACKAGE
14-LEAD PLASTIC SO
T
JMAX
= 150°C,
θ
JA
= 160°C/ W
MIN
TYP
35
55
75
150
180
200
1.5
1.8
2.0
0.40
±2
±3
±7
0.19
0.19
0.25
MAX
100
270
350
550
750
1000
30
45
50
3
±20
±35
±50
0.40
0.60
0.75
UNITS
µV
µV
µV
µV
µV
µV
mV
mV
mV
µV/°C
nA
nA
nA
µA
µA
µA
µA
µA
µA
●
●
–5
–8.4
–10
– 0.41
– 0.45
– 0.47
sn16789 16789fs
LT1678/LT1679
The
●
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
S
= 3V, V
CM
= V
O
= 1.7V; V
S
= 5V, V
CM
= V
O
= 2.5V unless
otherwise noted.
SYMBOL
I
OS
PARAMETER
Input Offset Current
CONDITIONS (Note 6)
(Note 11)
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
●
●
ELECTRICAL CHARACTERISTICS
MIN
TYP
4
5
8
6
10
15
0.1
0.1
0.15
90
180
1600
4.4
6.6
19
3.9
5.3
9
1.2
0.3
MAX
25
35
55
30
40
65
1.6
2.0
2.4
UNITS
nA
nA
nA
nA
nA
nA
µA
µA
µA
nV
P-P
nV
P-P
nV
P-P
nV/√Hz
nV/√Hz
nV/√Hz
V
S
= 5V, V
CM
= V
S
+ 0.1V
V
S
= 5V, V
CM
= V
S
– 0.3V, 0°C
≤
T
A
≤
70°C
●
V
S
= 5V, V
CM
= V
S
– 0.3V, – 40°C
≤
T
A
≤
85°C
●
V
S
= 5V, V
CM
= – 0.1V
V
S
= 5V, V
CM
= 0V, 0°C
≤
T
A
≤
70°C
V
S
= 5V, V
CM
= 0V, – 40°C
≤
T
A
≤
85°C
e
n
Input Noise Voltage
0.1Hz to 10Hz (Note 7)
V
CM
= V
S
V
CM
= 0V
f
O
= 10Hz
V
CM
= V
S
, f
O
= 10Hz
V
CM
= 0V, f
O
= 10Hz
f
O
= 1kHz
V
CM
= V
S
, f
O
= 1kHz
V
CM
= 0V, f
O
= 1kHz
i
n
V
CM
R
IN
C
IN
CMRR
PSRR
A
VOL
Input Noise Current Density
Input Voltage Range
●
●
●
Input Noise Voltage Density (Note 8)
5.5
nV/√Hz
nV/√Hz
nV/√Hz
pA/√Hz
pA/√Hz
f
O
= 10Hz
f
O
= 1kHz
– 0.1
0
V
S
+ 0.1V
V
S
– 0.3V
2
4.2
V
V
GΩ
pF
dB
dB
dB
dB
V/µV
V/µV
V/µV
V/µV
V/µV
V/µV
V/µV
V/µV
V/µV
V/µV
V/µV
V/µV
V/µV
V/µV
V/µV
V/µV
V/µV
Input Resistance
Input Capacitance
Common Mode Rejection Ratio
Power Supply Rejection Ratio
Large-Signal Voltage Gain
Common Mode
V
S
= 5V, V
CM
= 1.9V to 3.9V
V
S
= 5V, V
CM
= 1.9V to 3.9V
V
S
= 2.7V to 36V, V
CM
= V
O
= 1.7V
V
S
= 3.1V to 36V, V
CM
= V
O
= 1.7V
V
S
= 3V, R
L
= 10k, V
O
= 2.5V to 0.7V
V
S
= 3V, R
L
= 2k, V
O
= 2.2V to 0.7V
0°C
≤
T
A
≤
70°C
–40°C
≤
T
A
≤
85°C
V
S
= 3V, R
L
= 600Ω, V
O
= 2.2V to 0.7V
0°C
≤
T
A
≤
70°C
–40°C
≤
T
A
≤
85°C
V
S
= 5V, R
L
= 10k, V
O
= 4.5V to 0.7V
O°C < T
A
< 70°C
–40 < T
A
< 85°C
V
S
= 5V, R
L
= 2k, V
O
= 4.2V to 0.7V
0°C
≤
T
A
≤
70°C
–40°C
≤
T
A
≤
85°C
V
S
= 5V, R
L
= 600Ω, V
O
= 4.2V to 0.7V
0°C
≤
T
A
≤
70°C
–40°C
≤
T
A
≤
85°C
98
92
100
98
0.6
0.3
0.5
0.4
0.4
0.20
0.15
0.10
1
0.6
0.3
0.7
0.6
0.5
0.6
0.5
0.4
●
●
●
●
●
●
●
●
●
●
●
●
●
120
120
125
120
3
2
3
0.9
0.8
0.43
0.40
0.35
3.8
2
2
3.5
3.2
3.0
3.0
2.8
2.5
80
125
130
170
200
250
V
OL
Output Voltage Swing Low (Note 11)
Above GND
I
SINK
= 0.1mA
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
●
●
mV
mV
mV
sn16789 16789fs
3
LT1678/LT1679
The
●
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
S
= 3V, V
CM
= V
O
= 1.7V; V
S
= 5V, V
CM
= V
O
= 2.5V unless
otherwise noted.
SYMBOL
V
OL
PARAMETER
Output Voltage Swing Low (Note 11)
CONDITIONS (Note 6)
Above GND
I
SINK
= 2.5mA
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
Above GND
I
SINK
= 10mA
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
V
OH
Output Voltage Swing High (Note 11)
Below V
S
I
SOURCE
= 0.1mA
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
Below V
S
I
SOURCE
= 2.5mA
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
Below V
S
I
SOURCE
= 10mA
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
I
SC
Output Short-Circuit Current (Note 3)
V
S
= 3V
●
ELECTRICAL CHARACTERISTICS
MIN
TYP
170
195
205
370
440
465
75
85
93
110
195
205
170
200
230
MAX
250
320
350
600
720
770
150
200
250
250
350
375
400
500
550
UNITS
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mA
mA
mA
mA
V/µs
V/µs
V/µs
MHz
MHz
µs
µs
Ω
Ω
●
●
●
●
●
●
●
●
●
●
15
13
18
14
4
3.5
3
13
12.5
22
19
29
25
6
5.8
5.5
20
19
1.4
2.4
100
1
V
S
= 5V
●
SR
Slew Rate (Note 13)
A
V
= – 1, R
L
= 10k
R
L
= 10k, 0°C
≤
T
A
≤
70°C
R
L
= 10k, – 40°C
≤
T
A
≤
85°C
f
O
= 100kHz
f
O
= 100kHz
2V Step 0.1%, A
V
= +1
2V Step 0.01%, A
V
= +1
I
OUT
= 0
A
V
= 100, f = 10kHz
●
●
●
GBW
t
S
R
O
I
S
∆V
OS
Gain Bandwidth Product (Note 11)
Settling Time
Open-Loop Output Resistance
Closed-Loop Output Resistance
Supply Current per Amplifier (Note 12)
●
2
2.5
35
55
75
±2
±3
±7
94
88
96
94
110
110
120
120
3.4
3.8
150
400
525
±30
±55
±75
mA
mA
µV
µV
µV
nA
nA
nA
dB
dB
dB
dB
Offset Voltage Match
(Notes 11, 15)
Noninverting Bias Current Match
(Notes 11, 15)
Common Mode Rejection Match
(Notes 11, 14, 15)
Power Supply Rejection Match
(Notes 11, 14, 15)
0°C
≤
T
A
≤
70°C
–40°C
≤
T
A
≤
85°C
0°C
≤
T
A
≤
70°C
–40°C
≤
T
A
≤
85°C
V
S
= 5V, V
CM
= 1.9V to 3.9V
●
●
●
●
●
∆IB+
∆CMRR
∆PSRR
V
S
= 2.7V to 36V, V
CM
= V
O
= 1.7V
V
S
= 3.1V to 36V, V
CM
= V
O
= 1.7V
●
sn16789 16789fs
4
LT1678/LT1679
The
●
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
S
=
±15V,
V
CM
= V
O
= 0V unless otherwise noted.
SYMBOL
V
OS
PARAMETER
Input Offset Voltage
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
∆V
OS
∆Temp
I
B
Average Input Offset Drift (Note 10)
Input Bias Current
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
I
OS
Input Offset Current
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
e
n
Input Noise Voltage
0.1Hz to 10Hz (Note 7)
V
CM
= 15V
V
CM
= –15V
f
O
= 10Hz
V
CM
= 15V, f
O
= 10Hz
V
CM
= –15V, f
O
= 10Hz
f
O
= 1kHz
V
CM
= 15V, f
O
= 1kHz
V
CM
= –15V, f
O
= 1kHz
i
n
V
CM
R
IN
C
IN
CMRR
PSRR
A
VOL
Input Noise Current Density
Input Voltage Range (Note 16)
Input Resistance
Input Capacitance
Common Mode Rejection Ratio
Power Supply Rejection Ratio
Large-Signal Voltage Gain
V
CM
= –13.3V to 14V
●
●
●
●
●
●
●
●
ELECTRICAL CHARACTERISTICS
CONDITIONS (Note 6)
MIN
TYP
20
30
45
0.40
±2
±3
±7
3
5
8
90
180
1600
4.4
6.6
19
3.9
5.3
9
1.2
0.3
MAX
150
350
420
3
±20
±35
±50
25
35
55
UNITS
µV
µV
µV
µV/°C
nA
nA
nA
nA
nA
nA
nV
P-P
nV
P-P
nV
P-P
nV/√Hz
nV/√Hz
nV/√Hz
Input Noise Voltage Density
5.5
nV/√Hz
nV/√Hz
nV/√Hz
pA/√Hz
pA/√Hz
f
O
= 10Hz
f
O
= 1kHz
●
– 13.3
2
4.2
100
96
106
100
3
2
1
0.8
0.5
0.4
130
124
130
125
7
6
4
1.7
1.4
1.1
14
V
GΩ
pF
dB
dB
dB
dB
V/µV
V/µV
V/µV
V/µV
V/µV
V/µV
Common Mode
V
S
=
±1.7V
to
±18V
●
R
L
= 10k, V
O
=
±14V
0°C
≤
T
A
≤
70°C
–40°C
≤
T
A
≤
85°C
R
L
= 2k, V
O
=
±13.5V
0°C
≤
T
A
≤
70°C
–40°C
≤
T
A
≤
85°C
●
●
●
●
sn16789 16789fs
5
