1/4
OPA4131
VO
INA141
Ref
1/4
OPA4131
LA
RA
G = 10
20kΩ
20kΩ
390kΩ
VG
1/4
OPA4131
1/4
OPA4131
10kΩ
RL
390kΩ
FIGURE 4. ECG Amplifier With Right-Leg Drive.
V+
2
+5V
+15V
INA141
–15V
10.0V
6
2.5V – ∆V
2.5V + ∆V
REF102
R1
R2
VO
300Ω
4
Ref
Pt100
Cu
Cu
K
VO
INA141
Ref
FIGURE 5. Bridge Amplifier.
R3
100Ω = Pt100 at 0°C
–
VO
VIN
+
INA141
Ref
SEEBECK
COEFFICIENT
(µV/°C)
ISA
TYPE
R1
1MΩ
MATERIAL
R1, R2
C1
0.1µF
E
+ Chromel
58.5
66.5kΩ
76.8kΩ
97.6kΩ
102kΩ
– Constantan
J
+ Iron
– Constantan
50.2
39.4
38.0
1
f–3dB
=
K
T
+ Chromel
– Alumel
2πR1C1
OPA602
= 1.59Hz
+ Copper
– Constantan
FIGURE 6. AC-Coupled Instrumentation Amplifier.
FIGURE 7. Thermocouple Amplifier With RTD Cold-
Junction Compensation.
VIN
R1
–
R1
IO
=
• G
VIN
+
INA141
Ref
IB
IO
A1
Load
A1
IB Error
OPA177
OPA131
OPA602
OPA128
±1.5nA
50pA
±1pA
±75fA
FIGURE 8. Differential Voltage to Current Converter.
®
10
INA141
TI [ TEXAS INSTRUMENTS ]
