GSM/GPRS Modules
GSM Module Audio Design Guide
GSM Module Audo Design Guide Confidential/Release
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2.1.4. M80
2.1.4.1. Microphone Reference Circuit
M80 provides electrets-microphone bias voltage for AIN1 and AIN2. Reference circuit for microphone is
illustrated as following figure.
10pF
33pF
33pF
33pF
Close to Microphone
MICxP
MICxN
Differential layout
Module
Electret
Microphone
GND
GND
10pF
10pF
ESD
ESD
Figure 11
:
Microphone Reference Circuit for AIN1&AIN2
2.1.4.2. Receiver Reference Circuit
SPK1P
SPK1N
Differential layout
10pF
10pF
33pF
33pF
33pF
Close to speaker
GND
10pF
ESD
ESD
Module
GND
Figure 12
:
Receiver Reference Circuit for AOUT1
Quectel
Confidential