GSM/GPRS Modules
GSM Module Audio Design Guide
GSM Module Audo Design Guide Confidential/Release
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2.1.1.3. Headset Reference Circuit
Amphenol
9001-8905-
050
1
2
4
3
SPK2P
MIC2N
MIC2P
22uF
68R
AGND
Close to Socket
Differential
layout
AGND
Module
4.7uF
ESD
GND
33pF
10pF
33pF
GND
10pF
ESD
Figure 6
:
Headset Reference Circuit
2.1.2. M95
2.1.3. Microphone Reference Circuit
M95 module provides electrets-microphone bias voltage for AIN1 and AIN2. Reference circuit for
microphone is shown as bellow:
MICxP
Differential
layout
Module
10pF
33pF
33pF
33pF
Electret
Microphone
GND
GND
10pF
10pF
ESD
ESD
33pF
10pF
Close to Module
MICxN
GND
GND
GND
GND
10pF
33pF
33pF
10pF
Close to MIC
Figure
7
:
Microphone Reference Circuit for AIN1&AIN2
Quectel
Confidential