1/4
MC3403
e
o
V
CC
C
O
C
O
= 10C
C
R3
R2
R1
e
I
V
(ref)
V
(ref)
1
2
V
CC
=
C
Given f
o
= Center frequency ; choose values f
o
, C then R3 =
Q
πf
o
C
•
A (f
o
) = Gain at center frequency R1 =
R3
2A ( f
o
)
•
R2 =
R1 R5
4Q
2
R1− R5•
For less than 10% error from operational amplifier
Q
o
f
o
BW
< 0.1 where f
o
and BW are expressed in Hz
If source impedance varies, filter may be preceded with voltage follower buffer to stabilize filter parameters
MULTIPLE FEEDBACK BANDPASS FILTER
1/4
MC3403
V
(ref)
V
(ref)
1
2
V
CC
=
Triangle wave output
C
1/4
MC3403
R2
300k
Ω
Square wave output
R3
75k
Ω
R1
100k
Ω
V
(ref)
R1 + R2
4 CR R1
f =
f
if R3 =
R2 R1
R2 + R1
R
f
APPLICATION INFORMATION (continued)
FUNCTION GENERATOR
MC3303 - MC3403 - MC3503
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