MC3403 Datasheet, PDF (6/8 Pages) ON Semiconductor – QUAD DIFFERENTIAL INPUT OPERATIONAL AMPLIFIERS

MC3403 MC3303
Figure 9. High Impedance Differential Amplifier
Figure 10. Comparator with Hysteresis
e1
–
1/2
MC3403
+
1
C
R
R
a R1
R1
b R1
– _1/2
1
C
R
MC3403
e2
+
eo = C (1 +a +b) (e2 –e1)
–
1/2
MC3403
+
R
R2
VOH
R1
Vref
eo
Vin
–
1/2
MC3403
+
VO
VO
VOL
VinL =
R1
R1 +R2
(VOL –Vref) +Vref
VinH =
R1
R1 +R2
(VOH –Vref) +Vref
Vh =
R1
R1 +R2
(VOH –VOL)
Hysteresis
VinL VinH
Vref
Figure 11. Bi–Quad Filter
R
R
C1
R2
Vin
For: fo = 1.0 kHz
Q = 10
TBP = 1
TN = 1
C
–
1/2
MC3403
+
Vref
R2
C
–
1/2
MC3403
+
Vref
Bandpass
R1 ^Output
Where: TBP = center frequency gain
TN = passband notch gain
Vref
100 k
R3
–
1/2
MC3403
+
100 k
–
1/2
MC3403
+
Vref
C1
fo =
1
2πRC
R1 = QR
R2 = ^R1
TBP
R3 = TNR2
C1 = 10 C
Vref =
1
2
VCC
R = 160 kΩ
C = 0.001 µF
R1 = 1.6 MΩ
R2 = 1.6 MΩ
R3 = 1.6 MΩ
Notch Output
Figure 12. Function Generator
Vref =
1
2
VCC
Triangle Wave
Vref
Output
+
1/2
R3
MC3403
–
75 k
R1
100 k
C
Vref
Rf
f=
R1 +RC
4 CRf R1
if
R3 =
R2 R1
R2 +R1
R2
300 k
+
1/2
MC3403
–
Figure 13. Multiple Feedback Bandpass Filter
Vin
Square Wave
Output
C
R1
C
R2
VCC
R3
–
1/2
MC3403
+
CO
VO
CO = 10 C
Given:
Vref
fo = center frequency
A(fo) = gain at center frequency
Vref =
1
2
VCC
Choose value fo, C
Then: R3 = ^Q
π fo C
R1 = ^R3
2 A(fo)
R2 =
R1 R5
4Q2 R1 –R5
For less than 10% error from operational amplifier
where fo and BW are expressed in Hz.
Oo fo
BW
< 0.1
If source impedance varies, filter may be preceded with
voltage follower buffer to stabilize filter parameters.
6
MOTOROLA ANALOG IC DEVICE DATA