VREF5
0.01µF
See ISO124 data sheet
if isolation is needed.
1MΩ
VREF2.5
6kΩ
4.8kΩ
14
13
Isothermal
Block
20kΩ
7.5V to 36V
11
5
4
1
+
RLIN
VIN
OPA277
10
V+
VREG
IO
RG
4-20 mA
Type K
COUT
0.01µF
9
8
Q1
RG
1kΩ
B
E
XTR106
1MΩ(1)
VO
+
VPS
–
3
2
RG
VI–N
RL
IO
Lin
Polarity
1N4148
7
IRET
12
40
)
5.2kΩ
100Ω
6
IO = 4mA + VIN • (
RG
50Ω
V
REG (pin 1)
2kΩ
NOTE: (1) For burn-out indication.
0.01µF
FIGURE 7. Thermocouple Low Offset, Low Drift Loop Measurement with Diode Cold-Junction Compensation.
VREF2.5
VREG
See ISO124 data sheet
if isolation is needed.
VREF5
2.5V
14
Bridge
Sensor
RLIN
11
10
V+
1N4148
13
1
+12V
VI+N
5
4
1µF
–
+
RB
RG
9
8
16
10
RG
B
0.01µF
XTR106
11
3
12
3
2
RG
VI–N
E
7
15
14
IO
VO = 0V to 5V
Lin
Polarity
RCV420
2
13
IRET
5
12
4
6
1µF
IO = 4-20mA
NOTE: Lin Polarity shown connected to correct positive bridge
nonlinearity. See Figure 3b to correct negative bridge nonlinearity.
–12V
FIGURE 8. ±12V-Powered Transmitter/Receiver Loop.
®
15
XTR106
BB [ BURR-BROWN CORPORATION ]
