Product Info

Smart LTE Module Series
SC66 Hardware Design
SC66_Hardware_Design 28 / 139
193,
195,
219,
225,
243,
257~
323
Audio Interfaces
Pin Name Pin No. I/O Description
DC
Characteristics
Comment
MIC_BIAS 167 AO
Microphone bias
voltage
V
O
=1.6V~2.9V
MIC1_P 44 AI
Microphone input for
channel 1 (+)
MIC1_M 45 AI
Microphone input for
channel 1 (-)
MIC_GND 168
Microphone
reference ground
If unused, connect this
pin to the ground.
MIC2_P 46 AI
Microphone input for
headset (+)
Headset microphone
input.
MIC3_P 169 AI
Microphone input for
secondary
microphone (+)
Secondary microphone
input.
EAR_P 53 AO Earpiece output (+)
EAR_M 52 AO Earpiece output (-)
SPK_P 55 AO Speaker output (+)
SPK_M 54 AO
Speaker output (-)
HPH_R 51 AO
Headphone right
channel output
HPH_REF 50 AI
Headphone
reference ground
It should be connected
to main GND.
HPH_L 49 AO
Headphone left
channel output
HS_DET 48 AI
Headset insertion
detection
High level by default.
USB Interfaces
Pin Name Pin No. I/O Description DC Characteristics Comment