Reference Circuit Design For Headphone Interface; Reference Circuit Design For Loudspeaker Interface; Audio Interface Design Considerations - Quectel SC20-WL Hardware Design

3.21.3. Reference Circuit Design for Headphone Interface

MIC_GND
MIC2P
HPH_L
HS_DET
HPH_R
HPH_GND
Module
Figure 26: Reference Circuit Design for Headphone Interface

3.21.4. Reference Circuit Design for Loudspeaker Interface

EARP SPKP
EARN SPKN
Module
Figure 27: Reference Circuit Design for Loudspeaker Interface

3.21.5. Audio Interface Design Considerations

It is recommended to use the electret microphone. In order to decrease radio or other signal interference,
the position of RF antenna should be kept away from audio interface and audio trace. Power trace cannot
be parallel with audio trace and also should be far away from the audio trace.
The differential audio traces must be routed according to the differential signal layout rule.
SC20-WL_Hardware_Design
R1
0R
C2
C1
NM NM
R3
0R
R4
20K
0R
F4
C3 C4 C5
NM NM
F1
0R
F2
0R
R2
0R
F1 0R
F2 0R
F3 0R
D1 D2 D3 D4
NM
ESD
D1
C1 C2
NM NM
Smart Wi-Fi Module Series
SC20-WL Hardware Design
1
5
4
6
3
2
D2
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