Cirrus Logic AN168 - Manual (Page 30)

AN168
30 AN168REV2
Gain = R2/R1 C1 = 1/[2 * PI * R1 * (300 Hz)] C2 = 1/[2 * PI * R2 * (4 kHz)]
CS6422_A0
Filt_Out
Vbias
Vbias
+5V
+5V
U3 MC33202
+ -
U1 MC33202
+ - U2 MC33202
R2 12.1k
R4 16.2k
R5 10K
R1 12.1k
R6 10K
C1 0.047uF
C2 3300pF (COG)
C3 1200pF (COG)
C4 4700pF (COG)
C7 0.1uF
C5 0.47uF
+
C8 10uF
+
C6 10uF
R3 16.2k
Fi
g
u
re 21
.
Ex
am
pl
e
4
k
Hz, 3-
Po
le Butterworth Low-Pass
Filter