User's Manual

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Note d’étude / Technical document : URD1– OTL 5665.1– 002 / 70 884 Edition 03
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Figure 5 : Filter and ESD protection of microphone
3.2.1.2 Notes for speaker
As explained for the microphone, if the speaker is deported out of the board or is sensitive to ESD, use the
schematic here after to improve the audio.
Figure 6: Filter and ESD protection of 32 ohms speaker
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HSET_OUT_P, HSET_OUT_N tracks must be larger than other tracks: 0.1 mm.
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As described in the layout chapter, differential signals have to be routed in parallel (HSET_OUT_P and
HSET_OUT_N signals)
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The impedance of audio chain (filter + speaker) must be lower than 32 Ohm.
3.2.2 Recommended characteristics for the microphone and speaker
HiloNC
INTMIC_P
MIC
Ferrite Bead
18pF
ESD protection
HiloNC
HSET_OUT_P
HSET_OUT_N
speaker
Ferrite Bead
Ferrite Bead
18pF
18pF
ESD protection
ESD protection