Headset Reference Circuit; M95; Microphone Reference Circuit - Quectel GSM Series Audio Design Manual

2.1.1.3. Headset Reference Circuit

Module

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:
Module
MICxP
MICxN
GSM Module Audo Design Guide
Differential
layout
MIC2N
MIC2P
22uF
SPK2P
AGND
Figure 6：Headset Reference Circuit
Close to Module
GND
GND
10pF
33pF
10pF
33pF
10pF 33pF
GND GND
Figure 7 ：Microphone Reference Circuit for AIN1&AIN2
GSM Module Audio Design Guide
Close to Socket
4.7uF
10pF
33pF
68R
10pF
33pF
GND
Close to MIC
GND
Differential
layout
10pF
10pF
10pF
GND
Confidential/Release
GSM/GPRS Modules
GND
ESD
3
4
2
1
ESD
Amphenol
9001-8905-
AGND 050
ESD
33pF
33pF
Electret
Microphone
33pF
ESD
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