Schematics

5
5
4
4
3
3
2 1
D D
C C
B B
A A
MCU:AC6919A
BT-ANT
TEST POINT
USB
Bypass CAP
BAT
DAC
LED
KEY
MIC
BT-ANT
DACL
MIC
BT-ANT-IC OSC24MO
OSC24MI
OSC24MI OSC24MO
BT-ANT-IC
LEDB/R
DACR
PP/POWER
DACL
DACR
MIC
LEDB/R
BT-ANT
LEDB/R
MIC
PP/POWER
BATT+
3V3 DACVDD
BT_AVDD
GNDA
GND
GND
3V3
GND
BATT+
GNDA
DACVDD
BATT+
GND
GNDA
GND
RTCVDD
RTCVDD
BATT+
GND
GND
DC+5V
GND
GND
MCU-5V
MCU-5V
MCU-5V
GNDA
3V3
GND
BT_AVDD
GNDA
DACVDD
GND
RTCVDD
C11
NC
BATT+
ANT1
PCB_BT_ANT
1 2
C15
105
GND
R+
C9
NC
R5 6.8K
K1
PWR/PP/TEL
C5
105
Y1 24MHz/10PPM
1 3
2 4
R7 10R
L+
R8
470R
USB1
Micro-USB
VBUS
1
D-
2
D+
3
ID
4
GND
5
S1
6
S2
7
S3
9
S4
8
R17
22K
LED2
RED
R10
470R
R6 1K
R16 100K
LED1
BLUE
C4
105
B-
R15 220K
C6
104
DM
R-
K6
PREV/V-
K7
NEXT/V+
MK1
MIC
1
2
L1 0R
L-
C14
104
L2 0R
TP2
C13
NC
C10 104
DP
B+
C8
224
L3
2P7F
U1 AC6919A-SOP16
ADC/USBDM
11
MIC/PA0/ADC10/USBDP
12
DACR
13
DACL
14
DACVDD
16
ADC13/PR2
6
DACVSS
15
VDDIO
1
BT_OSCO
10
BT_OSCI
9
BT_RF
7
RTCVDD
5
BT_AVDD
4
LDO_IN
3
VSSIO
8
VBAT
2
R2
NC
L4 0R