Product Info

Smart LTE Module Series
SC20 Hardware Design
SC20_Hardware_Design 65 / 130
3.22. Audio Interfaces
SC20 module provides two analog input channels and three analog output channels. The following table
shows the pin definition.
Table 27: Pin Definition of Audio Interfaces
⚫ The module offers two audio input channels which are both single-ended channels.
⚫ The earpiece interface uses differential output.
⚫ The loudspeaker interface uses differential output as well. The output channel is available with a
Class-D amplifier whose output power is 879mW when VBAT is 4.2V and load is 8Ω.
⚫ The headphone interface features stereo left and right channel output, and headphone insert
detection function is supported.
Pin Name
Pin No
I/O
Description
Comment
MIC1P
4
AI
Microphone positive input for channel 1
MIC_GND
5
MIC reference ground
MIC2P
6
AI
Microphone positive input for channel 2
EARP
8
AO
Earpiece positive output
EARN
9
AO
Earpiece negative output
SPKP
10
AO
Speaker positive output
SPKN
11
AO
Speaker negative output
HPH_R
136
AO
Headphone right channel output
HPH_GND
137
AI
Headphone virtual ground
HPH_L
138
AO
Headphone left channel output
HS_DET
139
AI
Headset insertion detection
High level by default