Datasheet

OPA333
3V
NTC
Thermistor
1 MΩ
60 kΩ
100 kΩ
1 MΩ
V
1
−
In
V
2
+In
R
1
R
2
2
3
5
6
1
R
2
OPA333
OPA333
INA152
V
O
V
O
= (1 + 2R
2
/R
1
) (V
2
−
V
1
)
R
1
100k
Ω
1/2
OPA2333
RA
Inverted
V
CM
+V
S
INA321
(1)
+V
S
V
OUT
+V
S
+V
S
+V
S
OPA333
+V
S
1/2 V
S
dc
3
2
1
4
5
6
G
TOT
= 1kV/V
G
INA
= 5
G
OPA
= 200
f
LPF
= 150Hz
f
HPF
= 0.5Hz
(provides ac signal coupling)
V
S
= +2.7V to +5.5V
BW = 0.5Hz to 150Hz
f
O
= 0.5Hz
Wilson
V
CENTRAL
(RA + LA + LL)/3
7
ac
1/2 V
S
R
2
100k
Ω
1/2
OPA2333
LL
+V
S
R
3
100k
Ω
1/2
OPA2333
LA
R
4
100k
Ω
R
9
20k
Ω
R
6
100k
Ω
RL
+V
S
+V
S
1/2
OPA2333
1/2
OPA2333
1/2
OPA2333
C
4
1.06nF
C
3
1
µ
F
R
14
1M
Ω
R
12
5k
Ω
R
13
318k
Ω
R
7
100k
Ω
R
8
100k
Ω
R
10
1M
Ω
C
2
0.64
µ
F
R
11
1M
Ω
C
1
47pF
R
5
390k
Ω
NOTE: (1) Other instrumentation amplifiers can be used,
such as the INA326, which has lower noise,
but higher quiescent current.
OPA333-Q1
SBOS522 –JUNE 2010 www.ti.com
Figure 7. Thermistor Measurement Figure 8. Precision Instrumentation Amplifier
Figure 9. Single-Supply, Very-Low-Power ECG Circuit
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Product Folder Link(s): OPA333-Q1