Schematics
5
5
4
4
3
3
2
2
1
1
D D
C C
B B
A A
MCU:AC6908C
BLUETOOTH
MIC
USB
LEDB
LEDB
SP+
SP-
BT-ANT
MIC
DACL
MIC
LEDB
VCOM
BT-ANT-ICOSC24MO
OSC24MI
BT-ANT-IC
VCOM
MUTE
VCOMO
PP/POWER
LEDR
LEDB
PP/POWER
BT-ANT
DACL
OSC24MOOSC24MI
MUTE
GNDA
DACVDD
BATT+
3V3
DACVDD
BT_AVDD
GNDA
GND
GND
3V3
GND
BATT+
GNDA
DACVDD
BATT+
GND
GNDAGND
GND
BT_AVDD
GND
RTCVDD
RTCVDD
BATT+
GND
GND
DC+5V
GND
DC+5V
GND
GND
GND
RTCVDD
GND
GND
BATT+
GNDA
GND
BATT+
GND
DC+5V
GND
GND
DC+5V
BATT+
3V3
R40 10KR40 10K
K1
POWER
K1
POWER
C15
105
C15
105
BATT+BATT+
R41 10KR41 10K Q12
3904
Q12
3904
GNDGND
C1
10uF
C1
10uF
R42 100KR42 100K
ANT1
PCB_BT_ANT
ANT1
PCB_BT_ANT
1
2
U6
4054
U6
4054
STAT
1
VSS
2
VBAT
3
PROG
5
VDD
4
R22 120KR22 120K
R47 47K
R47
62
R19 20KR19 20K
C7
105
C7
105
C5
10uF
C5
10uF
BAT1
3.7V
BAT1
3.7V
1
2
CON1
SPEAK
CON1
SPEAK
1
2
K5
TEL
K5
TEL
R23
NC
R23
NC
K2
PREV/V-
K2
PREV/V-
C20 105C20 105
M-M-
R5 6.8KR5 6.8K
C13
NC
C13
NC
MINI-USBMINI-USB
VBUS
1
D-
2
D+
3
ID
4
GND
5
S1
6
S2
7
S3
9
S4
8
R39 NCR39 NC
C4
105
C4
105
LED1
BLUE
LED1
BLUE
R55 510RR55 510R
C1710uF C1710uF
C10 104C10 104
DMDM
R44 NCR44 NC
R17
22K
R17
22K
R43
10K
R43
10K
LED2 REDLED2 RED
U4 LPA2171U4 LPA2171
SD
1
BP
2
+IN
3
-IN
4
VO1
5
VDD
6
GND
7
VO2
8
C3 2P7FC3 2P7F
R21 51KR21 51K
R4
470R
R4
470R
K4
PP
K4
PP
R20 33KR20 33K
R18 0RR18 0R
C14
105
C14
105
K3
NEXT/V+
K3
NEXT/V+
C21
104 C21104
TP2TP2
Y1 24MHz/10PPMY1 24MHz/10PPM
1
2
3
4
M+M+
C8
105
C8
105
R53
3.3K
R53
3.3K
DPDP
U1 AC6908CU1 AC6908C
USBDM
3
USBDP
4
PB13/MIC/PA3/AUX1L/ADC0
5
VCOMO
7
DACL
6
DACVDD
8
VCOM
9
ADC13/PR2
18
DACVSS
10
VDDIO
11
BT_OSCO
2
BT_OSCI
1
BT_RF
19
RTCVDD
17
BT_AVDD
16
LDO_IN
15
VSSIO
20
VBAT
14
SW
13
PGND
12
R1 NCR1 NC