Smart Wi-Fi Module Series
SC20-WL Hardware Design
SC20-WL_Hardware_Design
59 / 81
3.21.3. Reference Circuit Design for Headphone Interface
NM
0R
20K
ESD
MIC_GND
MIC2P
HPH_L
HS_DET
HPH_R
HPH_GND
NM
0R
Module
C1
NM
C2
R1
R2
0R
R3
R4
0R
3
6
4
5
2
1
NM
NM
C3
C4
C5
F3
F2
F1
D1 D2 D3 D4
0R
0R
0R
F4
Figure 26: Reference Circuit Design for Headphone Interface
3.21.4. Reference Circuit Design for Loudspeaker Interface
EARP
EARN
F2
SPKP
SPKN
0R
0R
NM
NM
C1
C2
F1
Module
D1
D2
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.