Audio Interfaces - Quectel M12 Hardware Design

M12 Hardware Design
DCD
TXD
CTS
RI
GND
MODULE
RXD
DTR
RTS
3V

3.9. Audio interfaces

The module provides two analogy input channels and two analogy output channels.
Table 10: Pin definition of Audio interface
Interface Name
MIC1P
MIC1N
(AIN1/AOUT1)
SPK1P
SPK1N
MIC2P
MIC2N
SPK2P
(AIN2/AOUT2)
AGND
M12_Hardware_Design_V3.3
SP3238
28
C1+ V+
25
C1- GND
1
C2+ VCC
3
C2- V-
24
T1IN T4OUT
23
T2IN T2OUT
22
T3IN T3OUT
19
T4IN T1OUT
T5OUT
17
T5IN
16
/R1OUT
21
R1OUT R1IN
20
R2OUT R2IN
18
R3OUT R3IN
13
ONLINE
/STATUS
/SHUTDOWN
Figure 26: RS232 level match circuit
Pin
23
24
22
21
25
26
20
19
27
2
GND
26
3V
4
GND
10
6
7
5
12
8
9
11
15
14
TO PC serial port
Function
Microphone1 input +
Microphone1 input -
Audio1 output+
Audio1 output-
Microphone2 input +
Microphone2 input -
Audio2 output+
It is suggested AGND is used in audio
circuit. Do not connect it to digital
ground in host PCB which could produce
TDD noise.
1
6
2
7
3
8
4
9
5
GND
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