M10 Hardware Design
capacitor is recommended ) which usually for block the DC voltage in the single-end mode.
The module analogy output configuration is determined by control register settings and
established using analogy multiplexes.
z
These two analogy channels can be easily swapped by “AT+QAUDCH” command. For more
details, please refer to document [1].
z
For each channels, you can use AT+QMIC to adjust the input gain level of microphone, you
can also use “AT+CLVL” to adjust the output gain level of receiver and speaker.
“AT+QECHO” is to set the parameters for echo cancellation control. Also “AT+QSIDET” is
to set the side-tone gain level, use “AT+QAUDCH” to activate one of the two audio channels
and deactivate the other one. For details, please refer to document [1].
Note:
z
Use AT command “AT+QAUDCH” to select audio channel:
0--AIN1/AOUT1 (normal audio channel), the default value is 0.
1--AIN2/AOUT2 (aux_audio channel) .
Table 11: Pin definition of Audio interface
Interface
Name
Pin
Function
MIC1P 23 Microphone1
input
+
MIC1N 24 Microphone1
input
-
SPK1P 22 Audio1
(AIN1/AOUT1)
SPK1N 21 Audio1
output-
MIC2P 25 Microphone2
input
+
MIC2N 26 Microphone2
input
-
(AIN2/AOUT2)
SPK2P 20 Audio2
AGND
19
Suggest to be used in audio circuit. Don’t
connect to digital GND.
One of the following matching circuits can be chosen in order to improve audio performance. The
difference audio signals have to be layout according to differential signal layout rules. As show in
following figures
(Note: all components package are 0603.)
If you want to adopt an amplifier
circuit for audio, Texas Instruments’s TPA6205A1 which is a fully differential amplifier is
recommended. You can also select it according to your requirement.
M10_HD_V1.00
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