Schematics

FILE NAME :
SHEET NAME :
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CHECKED BY :
VERSION :
SHEET : 1/1
DATE :
DATE :
APPROVED BY: SIZE : A3DATE :
V01
2019-6-20
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
2.7P
C6
105
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
AGND
2 1
D3
BLUE
21
D5
RED
C20
105
C21
105
DP
DM
R8 30K
C5 224
C7
105
C9
106
SPK+
SPK-
1
SD
2
BYP
3
MODE
4
IN
5
VON
6
VDD
7
GND
8
VOP
9
GND
U4
MAX2108A
R10 30K
R11 30K
1
23
4 5
SW2
R3
100R
1
GND
2
OUT
3
LX
U2
C10
100uF/16V
C11
470uF/16V
12
L1
22UH
R4 NC
ADKEY
VMCU
USBDP
USBDP
USBDM
MUTE
+3.3V
GND
GND
LED_B/R
LED_B/R
VMCU
AGND
USBDM
5V
GND
GND
DACL
VCC
MUTE
DACL
VCC
GNDGND
GND
GND
GND
GND
VMCU