Earphone Interface Configuration - Quectel M12 Hardware Design

M12 Hardware Design
Module
SPK2P
AGND
Figure 31: Reference design with an amplifier for AOUT2
Note: The value of C1 and C2 depends on the input impedance of audio amplifier.

3.9.4. Earphone interface configuration

MIC2N
Module
MIC2P
SPK2P
AGND
AGND
Table 11: Typical electret microphone characteristic
Parameter
Working Voltage
Working Current
External Microphone Load Resistance
M12_Hardware_Design_V3.3
Differential layout
C1
C2
Differential
layout
22uF
Figure 32: Reference design for an earphone
10pF
0603
Amplifier
circuit
10pF
0603
Close to Socket
GND
4.7uF
10pF
33pF
0603
0603
68R
10pF
33pF
0603
0603
GND
Min Typ
1.2 1.5
200
2.2
Close to speaker
GND
33pF
ESD
0603
33pF
ESD
0603
GND
ESD
3
4
2
1
ESD
Amphenol
9001-8905-050
AGND
Max Unit
2.0 V
500 uA
k Ohm
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