Datasheet

15
®
XTR112, XTR114
FIGURE 6. Thermocouple Low Offset, Low Drift Loop Measurement with Diode Cold-Junction Compensation.
14
1
12
5V
11
13
I
REG
< 2mA
4
3
2
6
R
G
1250Ω
XTR112
XTR114
7
R
G
R
G
V
IN
–
V
IN
+
V
REG
I
R2
V+
I
RET
I
O
E
B
8
I
O
= 4mA + (V
IN
–V
IN
)
+–
40
R
G
9
10
1MΩ
0.01µF
20kΩ
OPA277
V+
V–
Type J
1N4148
Isothermal
Block
1MΩ
(1)
25Ω
50Ω
1kΩ
I
R1
V
LIN
R
CM
(2)
NOTES: (1) For burn-out indication.
(2) XTR112, R
CM
= 3.3kΩ
XTR114, R
CM
= 8.2kΩ
FIGURE 7. ±12V Powered Transmitter/Receiver Loop.
0.01µFQ
1
1N4148
–12V
1µF
5
4
2
3
15
13
14
11
10
12
1µF
V
O
= 0 to 5V
RCV420
16
+12V
8
7
9
E
B
14
11
12
13
4
3
2
XTR112
R
CM
1
0.01µF
R
Z
1370Ω
R
LIN1
18.7kΩ
R
G
1270Ω
RTD
Pt1000
100°C to
600°C
6
R
G
R
G
V
IN
–
V
IN
+
V
LIN
I
R1
I
R2
V
REG
V+
I
RET
I
O
10
I
O
= 4mA – 20mA
NOTE: A two-wire RTD connection is shown. For remotely
located RTDs, a three-wire RTD conection is recommended. R
G
becomes 1180Ω, R
LIN2
is 40.2kΩ. See Figure 3 and Table II.