R2
1000
900
800
700
600
500
400
300
P
I
OUTPUT POWER – mV
INPUT CURRENT – mA
S
S
R1
V
IN
+
-
-
V
A1
LED
A2
I
PD1
I
PD2
OUT
PD1
PD2
+
I
F
A) BASIC TOPOLOGY
200
100
0
V
R2
CC
C2
C1
R1
LED
R3
V
0
25
T
50
75
100 125 150 175
IN
-
-
– CASE TEMPERATURE – °C
S
V
A1
A2
PD1
PD2
PD2
OUT
+
+
Figure 11. Thermal Derating Curve
Dependence of Safety Limiting Value
with Case Temperature per VDE 0884.
B) PRACTICAL CIRCUIT
Figure 12. Basic Isolation Amplifier.
V
CC
V
IN
-
-
V
OUT
+
+
A) POSITIVE INPUT
B) POSITIVE OUTPUT
V
IN
-
-
V
OUT
+
+
C) NEGATIVE INPUT
D) NEGATIVE OUTPUT
Figure 13. Unipolar Circuit Topologies.
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AGILENT [ AGILENT TECHNOLOGIES, LTD. ]
