CA3193, CA3193A
Typical Applications
+15V
V+
a Va 3
+
7
6
R
R
CA3193
2-
4
-15V
R1
1K
R3
R
R + ∆R
R2 1K
9K
+15V
2- 7
6
CA3193
3+
b Vb
4
-15V
VOUT
=
–Va
RR-----21-
+
1
RR-----43-
+
Vb
RR-----43-
+
1
R4
9K
VOUT
For Ideal Resistors with RR-----12- = RR-----34-
VOUT
=
Vb
–
Va
RR-----43-
+
1
A
=
V---V--b--O--–--U---V-T---a-
=
R-R----43-
+
1
FOR VALUES ABOVE VOUT = (Vb - Va) (IO)
FIGURE 7. TYPICAL TWO OP AMP BRIDGE-TYPE
DIFFERENTIAL AMPLIFIER
R2
1M
2-
+15V
7
6
CA3193
3+
R1
2M
R3
4
-15V
2MΩ
R4
1M
RS
V
IL
R5
1K
RL
(0Ω TO 3.0kΩ)
WITH V = 1V
R2
20K
+15V
R1
V1
2- 7
10K
6
V2
R3
10K
CA3193
3+
R4
4
20K
-15V
VOUT
RL
ALL RESISTANCE VALUES ARE IN OHMS.
VOUT
=
V2
R-----3--R--+---4--R-----4-
-R----1--R--+---1--R-----2-
–
V1
RR-----21-
If R4 = R2, R3= R1 and RR-----21- = RR-----43-
THEN
VOUT
=
(
V2
–
V
1)
R-R----21-
For values above VOUT = 2(V2 - V1):
If AV is To be made 1 and if R1 = R3 = R4 = R
with R2 = 0.999R (0.1% mismatch in R2)
Then VOCM = 0.0005 VIN or CMRR = 66dB
Thus, the CMRR of this circuit is limited by
the matching or mismatching of this network
rather than the amplifier.
FIGURE 8. DIFFERENTIAL AMPLIFIER (SIMPLE
SUBTRACTER) USING CA3193
R3
V3
10K
RF
R2
20K
V2
10K
+15V
R1
V1
2- 7
10K
6
CA3193
3+
4
R4
-15V
RL
2.8K
ALL RESISTORS ARE 1%
IF R1 = R3 AND R2 ≈ R4 + R5, THEN
IL IS INDEPENDENT OF VARIATIONS IN RL
FOR RL VALUES OF 0Ω TO 3kΩ WITH V = 1V
IL = R--V---3--R-R---4--5- = (---2--V--M--(---1)---(M--1----K)----)- = 2--V--K--- = 500µA
FIGURE 9. USING CA3193 AS A BILATERAL CURRENT
SOURCE
VOUT
=
–
R-R----F1--
V
1
+
R-R----F2--
V2
+
R-R----F3--
V3
VOUT = - (2V1+ 2V2 + 2V3)
ALL RESISTANCE VALUES ARE IN OHMS.
FIGURE 10. TYPICAL SUMMING AMPLIFIER APPLICATION
66