Schematics

1 2 3 4
A
B
C
D
4
321
D
C
B
A
MCU
Earphone
、
、、
、
Power
KEY
、
、、
、
LED
L6 100K
AGND
BT_OSCO
BT_OSCI
+3.3V
VBAT
GND
L10 105
L7 105
L15
0R
BT_ANT
L2
1.2P
L16
1.5P
BT_RF
BT_ANT
DC5V
BT_OSCO BT_OSCI
Y1 24M
J1
Earphone
DACL
DACR
DACL
DACR
MIC
P/P/POWER
LED_B/R
L14 105
BT_AVDD
KEY
+
M1
MIC
MIC
L1
NC
BAT
3.4V~4.2V
VBAT
DC5V
DC5V input
USBDP
USBDM
VDDIO
1
VBAT
2
PB1/ADC5
6
DACVSS
15
ADC1/MIC/PA1
16
ADC14/USBDM
11
MIC_BIAS/PA2/PA3/USBDP
12
BT_OSCI
9
BT_OSCO
10
BT_RF
7
VSSIO
8
PB3/ADC6
5
DACL
14
LDO_IN/PB5
3
BT_AVDD
4
DACR
13
U1
AC6969A_SOP16
D3
WIE
D2
WIE
D1
WIE
LED_B/R
S7
P/P/POWER/TALK
P/P/POWER
J3
Earphone
DACL
DACR