11
–
I1
I2
10
+VCC
8
+VCC
3
OPA21
VREF
Out
R1
R2
XTR101
15V
0.01µF
4
+
7
2.5kΩ
VREF = ImA R2
FIGURE 19. Dual Precision Current Sources Operated From One Supply.
Isolation
Barrier
+15V
1µF
P+
+V2
C2
–
1kΩ
8
V+
E
722
–V2
1µF
C1 +V1 –V1
V–
4-20mA
+
30V
–
+15V
∆eIN
XTR101
7
1MΩ
15
10
+
+
–15V
1MΩ
12
7
9
2
4
3
250Ω
ISO100
(1)
VOUT
+1V to +5V
8
IREF2
17
–
16
18
NOTE: (1) Can be shifted and amplified
using ISO100 current sources.
IREF1
FIGURE 20. Isolated Two-Wire Current Loop.
®
13
XTR101