V+
+3V
2V –
∆V
R
1
300Ω
R
G
2V +
∆V
150Ω
R
1 (1)
INA118
Ref
Pt100
Cu
K
Cu
R
G
R
3
100Ω = RTD at 0°C
NOTE: (1) R
1
required to create proper common-mode voltage,
only for low voltage operation — see text.
ISA
TYPE
SEEBECK
COEFFICIENT
(
µ
V/
°
C)
58.5
50.2
39.4
38.0
3V
10.0V
6
REF102
2
R
2
4
V
O
INA118
Ref
V
O
MATERIAL
+ Chromel
– Constantan
+ Iron
– Constantan
+ Chromel
– Alumel
+ Copper
– Constantan
R
1
, R
2
66.5kΩ
76.8kΩ
97.6kΩ
102kΩ
FIGURE 5. Single-Supply Bridge Amplifier.
E
J
K
T
–
V
IN
+
R
G
INA118
Ref
C
1
0.1µF
V
O
R
1
1MΩ
FIGURE 7. Thermocouple Amplifier With Cold Junction
Compensation.
–
OPA602
1
f
–3dB
=
2πR
1
C
1
= 1.59Hz
R
1
R
G
INA118
Ref
I
B
A
1
I
O
=
V
IN
+
V
IN
•G
R
1
I
O
Load
FIGURE 6. AC-Coupled Instrumentation Amplifier.
A
1
OPA177
OPA602
OPA128
I
B
Error
±1.5nA
±1pA
±75fA
FIGURE 8. Differential Voltage to Current Converter.
2.8kΩ
LA
R
G
/2
2.8kΩ
390kΩ
RL
390kΩ
1/2
OPA2604
1/2
OPA2604
10kΩ
V
O
RA
INA118
Ref
G = 10
FIGURE 9. ECG Amplifier With Right-Leg Drive.
®
11
INA118
BURR-BROWN [ BURR-BROWN CORPORATION ]
