Schematics

+
M1
MIC
C10 NC
C19
104
C5
224
MIC
R3
6.8K
DACVDD
DACVDD
AGND
DACL
DACR
MIC
LED_B/R
BT_OSCO
BT_OSCI
+3.3V
C7 104
VBAT
GND
C8
224
C11 105
RTCVDD
BT_ANT
L4
1NH
L3
1NH
BT_RF
C9 105
P/P/POWER
BT_AVDD
BT_ANT1
LDO_IN
D1
BLUE
LED_B/R
D3
RED
R4
470R
+3.3V
VDDIO
1
VBAT
2
RTCVDD
5
DACVSS
15
DACVDD
16
ADC11/USBDM
11
MIC/PA0/ADC10/USBDP
12
BT_OSCI
9
BT_OSCO
10
BT_RF
7
VSSIO
8
BT_AVDD
4
DACL
14
LDO_IN
3
PR2/ADC13
6
DACR
13
U2
S3
P/P/POWER/TALK
P/P/POWER
C1
NC
R5
NC
BT_OSCO BT_OSCI
Y1 24M
J1
Earphone
L1
0R
L2
0R
C2
NC
C3
NC
DACL'
C12
NC
DACL
DACR
DACR'
BT1
3.4V~4.2V
VBAT
+5V LDOIN
+5V
1
DM
2
DP
3
ID
4
6
GND
6
6
6 6
USB2
USB(MICRO)
D2
10R
R6
1K
AC6919