60
DS726PP2
CS4525
6.4.2
Full-Bridge Output Filter (Stereo or Parallel)
shows the output filter for a full-bridge configuration. The transient-voltage suppression circuit
(snubber circuit) is comprised of a capacitor (680 pF) and a resistor (5.6
Ω,
1/8 W) on each output pin and
should be placed as close as possible to the corresponding PWM output pins to greatly reduce radiated
EMI. The inductors, L1, and capacitor, C1, comprise the low-pass filter. Along with the nominal load im-
pedance of the speaker, these values set the cutoff frequency of the filter.
shows the component
values based on nominal speaker (load) impedance for a corner frequency (-3 dB point) of approximately
35 kHz.
Load
L1, L2
C1
4
Ω
10 µH
1.0 µF
6
Ω
15 µH
0.47 µF
8
Ω
22 µH
0.47 µF
Table 20. Low-Pass Filter Components - Full-Bridge
OUTX+
OUTX-
C1
L1
L2
*Diode is Rohm
RB160M-30 or
equivalent
VP
VP
680 pF
5.6
Ω
680 pF
5.6
Ω
Figure 27. Output Filter - Full-Bridge