MeiG Smart product technical information
SLM500
Hardware Design Guide
Page 44
4.8.Audio Interface
The module provides three analog audio inputs, MIC_IN1_P for the main microphone,
MIC_IN2_P for the microphone, and MIC_IN3_P for the noise reduction microphone. The
module also provides three analog audio outputs (HPH_L/R, REC_P/N, SPK_P/N). The
audio pin is defined as follows:
Table 4.8
:
Audio Pin Definitions
Name
Pin
Input/Ou
tput
Description
MIC_IN1_P
4
I
Main MIC positive
MIC_IN2_P
6
I
Headphone MIC positive
MIC_GND
5
I
Headphone MIC, Headphone MIC
,
noise reduction MIC negative
MIC_IN3_P
148
I
Noise reduction MIC positive
MIC_BIAS1
147
O
BIAS voltage of the main MIC for
silicon wheat
MIC_BIAS2
155
O
BIAS voltage of the headphone MIC
for silicon wheat design
CDC_HPH_R
136
O
Headphone right channel
CDC_HPH_L
138
O
Headphone left channel
CDC_HSDET_L
139
I
Headphone plug detection
CDC_HPH_REF
137
I
Headphone reference ground
EAR_M
9
O
Earpiece output negative
EAR_P
8
O
Earpiece output positive
SPKR_OUT_M
11
O
Amplifier (0.7W) output negative
SPKR_OUT_P
10
O
Amplifier (0.7W) output positive
Users are advised to use the following circuit according to the actual application to get better sound
effects.
4.8.1Receiver Interface Circuit
Figure 4.21
:
Receiver Interface Circuit