Schematics

D
C
B
A
1 2 3 4 5 6
A
B
C
D
654321
MIC
POWER
LED
DAC
L1
0R
L3
NC
Y1
24MHz
C14
105
C18
NC
LED1
RED
P6
P7
P5
P8
LED2
BLUE
C1105
L2
NC
P11
P9
P10
P12
P13
P4
R1
5K1/NC
C2
105
1
2
3
A1
ANTBNE_2P
L5
0R
+
1 2
M1
C11
NC
L6
0R
L7
0R
C12
NC
C15
NC
1 2
A2
ANTBNE
A3
ANTENNA
P1
R3
1K
P2
P3
C6
1PF-50PF
1
VIM
2
VDD
3
GND
U2
R2
1K
C8
104
R4
0R
P15
10
BT_RF
7
VBAT
8
BT_AVDD
5
PB4
6
LDO_IN
4
PB6
2
DACR
18
PA1
16
USBDP
11
VSSIO
12
BT_OSCI
9
PB1
3
PB7
19
VDDIO
1
DACL
0
RFGND
17
PA2
20
DACVSS
13
BT_OSCO
14
PC5
15
USBDM
U1
AC6973A-QFN20 3*3
$$$13961
VBAT+
VBAT+
DC_5V
USBDP
USBDM
THC/P/P/POWER
DC_5V
USBDM
USBDP
DACL+
DACL-
VDDIO
VDDIO
MICIN
DACL+
DACL-
LED_B/R
VBAT+
THC/P/P/POWER
VBAT-
VBAT+
DC_5V
VBAT-
LED_B/R
MICIN
Builtin touch
electric circuit
Update point
Testing point
Charging box power
Charging
Battery