14
Figure 20. SPICE model listing.
Figure 19. Magnitude/sign isolation amplier.
-
+
V
MAG
-
+
V
IN
OC1
PD1
+
-
D4
C2 10 pf
C1 10 pf
D3
R4
680
OC1
LED
R1
220 K
C3 10 pf
OC1
PD2
R5
180 K
R6
50 K
GAIN
R2
10 K
R3
4.7 K
D1
-
+
D2
+
-
R7
6.8 K
V
CC
R8
2.2 K
V
SIGN
OC2
6N139
V
CC1
= +15 V
V
EE1
= -15 V
