
WA_DEV_W228_PTS_002 Rev
001
Page 65 of 108
Product Technical Specification &
Customer Design Guidelines
Figure 28. Single-Ended Audio Connection
Caution: It is a must to avoid digital tracks crossing under and over the audio tracks.
Even when MICP is singled-ended, it is highly recommended to have the MIC ground and the LC
filter ground to act as an audio analog ground during the PCB layout. This audio ground, together
with the MICP signal, should act as the differential line pair. And this audio ground should only be
connected to the WISMO228 module ground as close as possible to the castellation GND pin of the
WISMO228.
The same case is applicable to SPKP and SPKN.
Also, the audio interface is ESD sensitive. It is a must to add ESD protection to the interface once it
is externally accessible. The recommended ESD protection is the ESDA6VIL from ST.
Содержание WISMO228
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