cs4412a Cirrus Logic, Inc., cs4412a Datasheet - Page 18

• Manufacturer Part Number: cs4412a
• Description: 30w Quad Half-bridge Digital Amplifier Power Stage
• Manufacturer: Cirrus Logic, Inc.

18
4.4.2
Full-Bridge Output Filter (Stereo or Parallel)
Figure 6
(snubber circuit) is comprised of a capacitor (680 pF) and a resistor (5.6 Ω) 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 L2, and capacitor, C1, comprise the low-pass filter. Along with the nominal load imped-
ance of the speaker, these values set the cutoff frequency of the filter.
ues based on nominal speaker (load) impedance for a corner frequency (-3 dB point) of approximately
35 kHz.
Each output pin must be connected to two Schottky diodes—one to ground and one to the VP supply.
These diodes should be placed within 12 mm of the corresponding OUTx pin. The requirements of this
diode are:
1. Rated I
2. Support up to 80°C of lead temperature with V
3. V
at the corresponding I
R
(reverse voltage) is greater than or equal to 20 V.
shows the output filter for a full-bridge configuration. The transient-voltage suppression circuit
F
(average rectifier forward current) is greater than or equal to 1.0 A.
OUTX+
OUTX-
F
.
680 pF
680 pF
5.6 Ω
5.6 Ω
Table 6. Low-Pass Filter Components - Full-Bridge
Load
4 Ω
6 Ω
8 Ω
Figure 6. Output Filter - Full-Bridge
VP
VP
*Diode is Rohm
RB160M-30 or
equivalent
L1, L2
10 µH
15 µH
22 µH
F
drop (forward voltage) less than or equal to 480 mV
L1
L2
C1
Table 6
0.47 µF
0.47 µF
1.0 µF
C1
shows the component val-
CS4412A
DS786A2