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