LTE Module Series
Smart EVB User Guide
Smart_EVB_User_Guide Confidential / Released 17 / 29
The following figure shows the sketch of audio jack which matches the Smart EVB.
2
1
MIC
GND
SW
SPK_R
SPK_L
3
4
32Ω
32Ω
Figure 10: The Sketch of Audio Jack
3.3.3. MIC and Speaker
SMT U701 MIC is used for microphone and speaker is soldered on TP703 and TP704. The following
figure shows the schematic of the MIC and Speaker.
ESD
33pF
ESD
ESD
ESD
33pF
33pF
33pF
100pF
100pF
MIC1_P
MIC1_N
EAR_P
EAR_N
FB
EVB
M
IC
_
B
IA
S
HPH_R
HPH_L
U701 MIC
TP703
TP704
REC
Figure 11: MIC and Speaker Circuit
4
DETECT
Earphone detection
5
L-AUDIO
Earphone left channel
6
GND
Dedicated GND for audio
Quectel
Confidential
