User guide

M80 EVB User Guide
M80_EVB_UGD_V1.2 - 16 -
Table 3: Pins of AIN2/AOUT2
Pin
Signal
I/O
Description
Note
2_1
MIC2N
I
Negative microphone input
2_2
AGND
AGND of audio circuits
2_3
SPK2P
O
Positive receiver output
2_4
MIC2P
I
Positive microphone input
Table 4: Pins of AIN1/AOUT1
Pin
Signal
I/O
Description
Note
1_1
MIC1N
I
Negative microphone input
1_2
SPK1N
O
Negative receiver output
1_3
SPK1P
O
Positive receiver output
1_4
MIC1P
I
Positive microphone input
The handset which suits for the M80 EVB is different from the common handset and Quectel does
not provide this handset. The following picture illustrates a connection between RJ11 and the
handset. Customer can refer to the following picture to make a handset which suits for the M80
EVB.
RJ11
Handset
3
2
SPKN
SPKP
4
1
+
-
MICN
MICP
33pF
10pF
Mic
Figure 11: Connection between handset and RJ11
3.3.2. Earphone
AIN2/AOUT2 can be also designed as earphone. The schematic is shown as below. ADC0 and
EINT are used for earphone auxiliary function (etc: detect earphone, establish or reject phone call),
but this function is not supported in standard module.
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