Schematics

LI_3.7-4.4V
1
VDDIO
2
VBAT
3
LDO_IN/PB5
4
BT_AVDD
5
PB3/ADC6
6
PB1/ADC5
7
BT_RF
8
VSSIO
9
BT_OSCI
10
BT_OSCO
11
ADC14USBDM
12
MIC_BIAS/PA2/PA3/PA4/USBDP
13
DACR
14
DACL
15
DACVSS
16
ADC1/MICPA1
U1
AC6969A
C1
105
C2
105
C3 0R
C6
105
C8 106
Y2
24M/12pF
1
BT_ANT
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 3.9K
R7
1K
SW1
AGND
+
MIC1
C4
104
R1 6.8K
C5 106 C10 104/25V
C11
104/25V
C12 NC
C13
NC
C14
473/25V
C15
NC
1
2
3
Q1
AO3400
COLL1
COLL2
C16
473/25V
R4
10K
1
2
3
Q2
AO3400
D2
IN5819
D4
IN5819
1
2
3
Q3
AO3400
R5
1K
D6
BZT52C4V3
C17
105
C18
104
R8
33K 1%
R9
4.7K 1%
1
2
3
Q4
SI2301
R10
10K
R11
1K
1
DECODE
2
VSS
3
AD_VRECT
4
USB_IN/VPP
5
4V3
6
EN/PGC
U4
SQ511B
C19
226
2 1
D1
RED
2 1
D3
BLUE
21
D5 RED
C20
105
C21
105
DP
DM
R+
L+
1
NC
2
GND
3
FB
4
EN
5
VIN
6
SM
U5
LP6498A
L1
15uH/CD32
R14
51K/1%
R15
6.2K/1%
C23
226
R-
L-
D7
IN5819
D8
IN5819
D9 IN5819
R3 3.9K
D10
IN5819
ADKEY
VMCU
USBDP
USBDP
USBDM
MUTE
+3.3V
GND
GND
LED_B/R
+3.3V
LED_B/R
GND
VMCU
AGND
ADKEY
USBDM
GND GND
GND
GND
VIN
GND
GND
VSEN
GND
AC
GND
5V
AC
GND
4.3V
4.3V
GND
GND
GND
GND
5V
GND
DACL
DACR
DACL
DACR
GND
CH_DET
CH_DET
CH_DET