Datasheet

10
®
INA115
FIGURE 5. Providing an Input Common-Mode Current Path.
FIGURE 4. Optional Trimming of Output Offset Voltage.
47kΩ47kΩ
10kΩ
Microphone,
Hydrophone
etc.
Thermocouple
Center-tap provides
bias current return.
INA115
INA115
INA115
INA115
V
IN
V
IN
R
G
–
+
10kΩ
V
O
OPA177
Ref
±10mV
Adjustment Range
100Ω
100Ω
100µA
1/2 REF200
100µA
1/2 REF200
V+
V–
FIGURE 3. Switched-Gain Instrumentation Amplifier (improved gain drift).
R
1
R
2
R
3
R
4
R
5
R
6
R
7
GAIN STEPS (Ω)(Ω)(Ω)(Ω)(Ω)(Ω)(Ω)
1, 10, 100, 1000V/V 18k 1.8k 180 40 180 1.8k 18k
1, 2, 4, 8V/V 18k 9k 4.5k 9k 4.5k 9k 18k
1, 2, 5, 10V/V 18k 10.8k 3.6k 7.2k 3.6k 10.8k 18k
0, +3, +6, +9dB 18k 12.74k 9.02k 43.7k 9.02k 12.74k 18k
A
0
A
1
Gain
LL 1
HL
LH
H H Highest
A
1
A
2
A
3
12
11
10
25kΩ25kΩ
25kΩ25kΩ
13
7
5
4
V
IN
V
IN
INA115
V
O
–
+
Over-Voltage
Protection
25kΩ
25kΩ
Over-Voltage
Protection
Feedback
15
14
3
2
8
1
NC
NC
HI-509
–15V
+15V
16
1
2
14
3
15
8
9
4
5
6
7
10
11
12
13
R
1
R
2
R
3
R
4
R
5
R
6
R
7
A
1
A
0
Enable