Schematics

FILE NAME :
SHEET NAME :
DRAWN BY :
CHECKED BY :
VERSION :
SHEET : 1/1
DATE :
DATE :
APPROVED BY: SIZE : A3DATE :
V01
2019-6-20
LI_3.7-4.4V
Y2
24M/12pF
C35
105
C6
105
D2
BULE
VCC
GND
5
GND
4
GND
3
D-
2
D+
1
VCC
6
GND
7
GND
8
GND
9
GND
USB-MICRO
D1
RED
C8
2.7P
TXD
1
VDDIO
2
VBAT
3
LDO_IN
4
BT_AVDD
5
PB2/ADC12
6
PB1/ADC6
7
BT_RF
8
VSSIO
9
BT_OSCI
10
BT_OSCO
11
ADC11/USBDM
12
ADC10/PA3/USBDP
13
DACR
14
DACL
15
DACVSS
16
ADC0/MIC/PA1
U2
AC6939B
C1
105
C2
105
RXD
R1 NC
R2 0R
MIC+
MIC-
1
/CHRG
2
GND
3
BAT
4
VCC
5
PROG
U3
LTC4054
R3 1K
R4
3.3K
L+
R+
C5
NC
D3
BULE
R5 22R
L-
R-
SW2
P/P
1
BT_ANT
AGND
C3
106
C9
106
BAT+
VUSB
VUSB
BAT+
BT_AVDD
USB_DP
DACL
DACR
+3.3V
AGND
LED_B/R
LED_B/R
DACR
DACL
+3.3V