CS4525(2008) View Datasheet(PDF) - Cirrus Logic

Part Name

Description

MFG CO.

CS4525
(Rev.:2008)

30 W Digital Audio Amplifier with Integrated ADC

Cirrus Logic 

6.4.2

CS4525

Full-Bridge Output Filter (Stereo or Parallel)

Figure 27 shows the output filter for stereo full-bridge and parallel full-bridge output configurations. Tran-

sient voltage suppression circuits are implemented as a RC snubber networks comprised of resistors Rs

(5.6 Ω, 1/8 W) and capacitors Cs (680 pF). These should be placed as close as possible to the corre-

sponding output pin. These circuits decrease the slew rate of the output signal and reduce high frequency

ringing which can lead to increased EMI. The Schottky diodes protect the body diodes of the output de-

vices by conducting load current during switching transitions; these diodes must be present to ensure

proper device operation.

VP

CS4525

OUT+

Cs

680 pF

Rs

5.6 Ω

D1*

L1

D2*

* ROHM RB160 M-30

or equivalent

C1

OUT-

Cs

680 pF

Rs

5.6 Ω

VP

D3*

L2

D4*

Figure 27. Output Filter - Full-Bridge

The inductors L1 and L2 along with capacitor C1 form the low-pass filter. These values combine with the

nominal load impedance of the speaker to set the cut-off frequency of the filter. Table 20 shows the com-

ponent values based on nominal speaker impedance for a corner frequency of approximately 35 kHz

(-3 dB).

Load

4Ω

6Ω

8Ω

L1, L2

10 µH

15 µH

22 µH

C1

1.0 µF

0.47 µF

0.47 µF

Table 20. Low-Pass Filter Components - Full-Bridge

60

DS726PP3

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