LTE Module Series
M.2 EVB User Guide
M.2_EVB_User_Guide 22 / 37
The following figure shows the sketch design of audio plug which suits for the audio jack on M.2 EVB.
2
1
MIC
GND
SW
SPK_R
SPK_L
3
4
32
Ω
32
Ω
Figure 15: Sketch of Audio Plug
4.4.3.
Handset Interface (J303)
Audio interface J303 is designed for handsets. A reference circuit design for handset interfaces J303 is
shown below.
ESD
33pF
ESD
ESD
ESD
33pF
33pF
33pF
33pF
33pF
10pF
10pF
10pF
10pF
10pF
10pF
IN2P
IN2N
LOUDL/P
LOUDR/N
FB
J303
U101
Codec
TE-A
4
1
3
2
BTB CON
J301
Figure 16: Reference Circuit Design for Handset Interface J303
2
AGND
Dedicated GND for audio
3
SPK_R
Right channel of stereo audio output
4
SPK_L
Left channel of stereo audio output
5, 6
NC
Not connected
