Microphone Interface Design - Quectel EG915U-EU Manual

should be far away from the audio traces.
The differential audio traces must be routed according to the differential signal layout rule.

4.1.2. Microphone Interface Design

The microphone channel reference circuit is shown in the following figure.
MIC_BI AS
MIC_P
Module
MIC_N
NOTE
MIC channel is sensitive to ESD, so it is not recommended to remove the ESD components used for
protecting the MIC.
EG915U-EU_Hardware_Design
Close to Module
510R
1. 5K
100nF
1K
2. 2uF
1K
100nF
1. 5K
510R
Figure 16: Reference Design for Microphone Interface
Differential
10 pF
layout
10 pF
10 pF
LTE Standard Module Series
Close to
Microphone
33 pF
TVS
0R
33 pF
0R
Microphone
TVS
33 pF
Electret
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