Schematics

LI_3.7-4.4V
1
PB7/ADC9
2
LDO_IN/PB5
3
VBAT
4
VDDIO
5
PB1/ADC5
6
PB0
7
BT_RF
8
VSSIO
9
BT_OSCI
10
BT_OSCO
11
ADC14/USBDM
12
ADC3/ADC13/PA4/USBDP
13
ADC1/MIC/PA1
14
DACVSS
15
VCOM
16
DACL
U1
AC6969E
C1
105
C2
105
C3 0R
Y2
24M/12pF
VCC
GND
5
GND
4
GND
3
D-
2
D+
1
VCC
6
GND
7
GND
8
GND
9
GND
USB-MICRO
1
/CHRG
2
GND
3
BAT
4
VCC
5
PROG
U3
ME4084
R2 5.6K
R7
1K
AGND
21
D3
BLUE
21
D5
RED
C20
105
C21
105
DP
DM
R4 10K
C7
224
C9
105
C11
106
1
SD
2
BYPASS
3
AD/D
4
INN
5
VON
6
VDD
7
GND
8
VOP
9
GND
U2
HAA2108
SP+1
SP-1
1
2
CN1
1
2 3
4 5
SW4
1
ANT1
1
2
CN3
R1 10K
5
GND
4
GND
3
D-
2
D+
1
VCC
6
GND
7
GND
8
GND
9
GND
USB-MICRO1
BAS-5V
BAS-GND
5V
GND1
21
D1
BLUE
2 1
D2
BLUE
2 1
D4
BLUE
21
D6
BLUE
1
2
3
CN13
1
2
3
CN5
2 1
D7RED
R81 1K
D15
5819
C4NC
C8NC C10NC
R8 10K
R9 100K
1
2
3
Q1
R10 2K
R3 1M
R6 1K
C5
105
USBDP
USBDP
USBDM
MUTE
GND
GND
ON/OFF_DET
LED_B/R
GND
BAT+
AGND
USBDM
GND
DACL
DACL
VMCU
MUTE
GND
GND
LED_B/R
ON/OFF_DET
VMCU
+3.3V
BAT+DC_DET
DC_DET
+3.3V
GND
LED_A
USBDP
USBDM