CDB35L00-X4 Datasheet, PDF (6/12 Pages) Cirrus Logic – 2.7 W x 4 CS35L00 Amplifier Demonstration Board

CDB35L00-X4
1.6 Differential Analog Inputs
The differential audio inputs into the four CS35L00 devices are provided by the 3-pin headers (J10, J20,
J30, and J40) through DC blocking capacitors (C11, C12, C21, C22, C31, C32, C41, C42). The DC blocking
capacitors allow for an analog source to connect directly to the CS35L00, regardless of any DC bias that
may be present between the analog audio source’s outputs and the CS35L00 inputs.
1.7 Speaker Outputs
The four CS35L00 power outputs pairs are each configured for a single, full-bridge, audio channel. The out-
puts are routed through an optional EMI output filter and then presented at the J11, J21, J31, and J41 head-
ers. The CS35L00 is intended to be used with a 4 to 8 load.
1.7.1
Optional Speaker Output EMI Filter Components
The CDB35L00-X4 contains optional placeholders for a series ferrite bead (FB11, FB12, FB21, FB22,
FB31, FB32, FB41, FB42) and shunt capacitor (C16, C17, C26, C27, C36, C37, C46, C47) output filter.
For most applications with very short speaker leads between the CS35L00 and the speaker, use of these
components will not be necessary. However, for systems with long signal paths between the CS35L00
and the speaker or if the system requires connecting to cables off the PCB, it is suggested that the ferrite
bead and capacitor are populated with the recommended values shown in Table 6 on page 10. These op-
tional output filters will reduce EMI between the CS35L00 speaker outputs and the load.
In order to use the optional output filter ferrite beads for U1, the traces between the FB11 pads and the
traces between the FB12 pads must be cut to break the bypass circuit, before populating FB11 and FB12
with the desired component values. The location of these required cuts are shown in below in Figure 3.
The optional output filter ferrite beads for U2, U3, and U4 can be added in the same manner as described
for U1 (above). The optional output filter capacitors can be populated with or without the addition of the
ferrite beads and require no board modifications.
Cut the bypass
traces before insert-
ing the optional
input gain adjust-
ment resistors
Cut the bypass
traces before
inserting the
optional output fil-
ter ferrite beads
Figure 3. Optional Bypass Trace Cut Locations for U1
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DS913DB2