LTE Module Series
LTE OPEN EVB User Guide
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4.5.2. Analog Audio Interfaces (J0805/J0801/J0802)
4.5.2.1. Loudspeaker Interface (J0805)
Audio interface J0805 is designed for loudspeakers and the following figure shows a reference design of
loudspeaker with an external Class-D audio amplifier. If loudspeaker function is intended to be used,
please insert the jumper cap on J0803.
LOUDL/P
LOUDR/N
Differential layout
Amplifier
circuit
10pF
10pF
33pF
33pF
Close to speaker
GND
GND
ESD
ESD
Codec
FB
FB
C1
C2
J0805
U0101
ALC5616/
TLV3104
NCP2823
BTB CON
J0804
U0801
J0803
VBAT
VP
Figure 16: Reference Circuit Design for Loudspeaker Interface J0805
4.5.2.2. Earphone Interface (J0802)
Audio interface J0802 is designed for earphones. A reference circuit design for earphone interface J0802
is shown as following figure.
SPK_L
MIC_N
MIC_P
75pF
GND
GND
AGND
Close to Socket
Differential layout
15pF
10pF 33pF
GND
GND
AGND
Codec
ALC5616
TLV3104
Close to Socket
AGND
ESD
ESD
Audio Jack
22uF
U0101
J0802
1
4
5
3
2
SPK_R
10pF
33pF
22uF
6
MIC_P
0R
N
M
_0
R
33pF
GND
AGND
0R
NM_0R
10pF
4.7uF
BTB CON
J0804
Figure 17: Reference Circuit Design for Earphone Interface J0802