Quectel SC690A Series Hardware Design page 24

LDO9_1V8
VPH_PWR
VRTC
GND
Analog Audio Interfaces
Pin Name
MIC_BIAS1
MIC_BIAS2
MIC_BIAS3
MIC1_P
MIC1_M
MIC2_P
MIC2_M
MIC3_P
MIC3_M
EAR_P
EAR_M
LINE_OUT_P
SC690A_Series_Hardware_Design
9 PO 1.8 V output
Power supply for
220, 221 PO
peripherals
Power supply for
16 PIO
RTC
3, 4, 18, 20, 31, 34, 35, 40, 43, 47, 56, 62, 87, 98, 101, 112, 125, 128,130, 133,
135, 148, 150, 159, 160, 163, 170, 173, 176, 182, 193, 195, 219, 227, 243, 257–
323
Pin No. I/O Description
Microphone bias
44 AO
output voltage 1
Microphone bias
233 AO
output voltage 2
Microphone bias
167 AO
output voltage 3
Microphone input
218 AI
for channel 1 (+)
Microphone input
217 AI
for channel 1 (-)
Microphone input
216 AI
for channel 2 (+)
Microphone input
215 AI
for channel 2 (-)
Microphone input
214 AI
for channel 3 (+)
Microphone input
213 AI
for channel 3 (-)
53 AO Earpiece output (+)
52 AO Earpiece output (-)
Aux amplifier output
181 AO
(+)
Smart Module Series
It is suggested to
use a TVS to
increase voltage
surge withstand
capability.
Power supply for
external GPIO's
Vnom = 1.8 V
I max = 300 mA pull up circuits and
O
level shift circuit.
Vmax = 4.4 V
Vmin = 3.55 V
Vnom = 3.8 V
Vmax = 3.2 V
V = 2.0–3.25 V
I
DC
Comment
Characteristics
Vmin = 1.0 V
Vmax = 2.85 V
Used for headset
mic by default.
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