12 Example Application Schematic
G
-TW
-00
0
7441.6
.2
26MHz
XT1
15nH
L4
15nH
L5
VBAT
VBUS
3V3_USB
VBAT
1V8_SMPS
MFB
S1
4u7
L2
1V35_SMPS
1V8_SMPS
STAR
SP100
MI
C
_1
N
MIC
_1
P
MI
C
_B
IA
S
MIC
_2
P
MIC
_2
N
SPK
R
_L
N
SPK
R
_L
P
SPK
R
_R
N
SPK
R
_R
P
PIO_0
LED_1
LED_0
PIO_1
PIO_2
PIO_3
PIO_4
PIO_5
PIO_6
PIO_7
PIO_8
PIO_9
AIO_0
USB_P
USB_N
SPI_PCM#
LED_2
PIO_12
PIO_13
PIO_10
PIO_11
PIO_14
PIO_15
PIO_16
PIO_17
PIO_18
PIO_19
PIO_20
PIO_21
MIC_1
MIC_2
ANT
BT_RF
CH
G
_E
X
T
VB
A
T
_S
E
N
S
E
OUT
2
IN
4
GND
1
GND
3
2.45GHz
U2
RSTB
2u2
C1
2u2
C2
2u2
C3
2u2
C4
10n
C5
10n
C6
470n
C10
15p
C8
15p
C17
PIO
Bluetooth RF
Speakers (16
Ω
to 32
Ω
)
Left
Right
Dual-microphone Inputs
Mic1
Mic2
2u2
C12
Values of C13 to C16 can be reduced
at trade-off of bass response
or to minimise wind noise
2k2
R2
2k2
R1
4u7
L1
15p
C18
2u2
C13
2u2
C14
2u2
C15
2u2
C16
2u2
C9
4u7
C7
100n
C11
3V
3_U
S
B
J9
V
D
D
_A
UDI
O
A7
V
D
D_
DI
G
_M
E
M
K2
V
D
D_
P
A
DS
_1
E5
VS
S
_B
T
_R
F
B3
BT_RF
A3
CSR8640 BGA
VD
D
_AN
A
_R
A
D
IO
C2
V
DD_
A
U
X
B2
VD
D
_P
A
D
S
_2
E6
MI
C
_B
IA
S
B9
AU
_R
E
F
A8
V
R
EGEN
A
B
L
E
K4
VC
H
G
K5
VB
AT
K7
L
X
_1V
8
K6
BYPASS REG
CHARGER
DIG LDO
AUX LDO
ANA LDO
MIC BIAS
V
S
S
_S
M
P
S
_1V
35
K9
3V3
1V35
1V35
V
R
E
G
IN
_D
IG
K3
VBAT
1V8 SMPS
1V35 SMPS
L
X
_1V
35
K8
S
M
P
S
_1V
35_
S
E
N
S
E
K1
0
V
D
D
_AU
X_
1V
8
A1
1V35
V
S
S_
SM
PS_
1V
8
J8
E9
J3
C1
B1
D2
K1
J2
B10
H10
J10
E2
F2
D1
F1
H2
G2
G1
VD
D
_AU
D
IO
_D
R
V
B5
VS
S
_B
T
_L
O
_A
U
X
A2
F5
CH
G
_E
X
T
J6
VB
AT
_S
E
N
S
E
J7
VS
S
_D
IG
F6
VS
S
_A
U
D
IO
A5
SPK
R
_R
N
B6
SPK
R
_R
P
A6
SPK
R
_L
N
B4
SPK
R
_L
P
A4
D9
E1
J1
J4
H1
J5
G10
S
M
P
S
_1V
8_S
EN
S
E
H9
G9
F10
E10
F9
C9
C10
D10
MI
C
_A
P
A9
MIC
_A
N
A1
0
MIC
_B
P
B7
MIC
_B
N
B8
PCB Layout Notes
Ensure the following components are placed next to CSR8640 BGA
and have good low impedance connections both to signal and GND
C2 and C3
Ensure the following tracks have good low impedance connections
(no via share and short thick tracks)
VSS_SMPS_1V8 to Battery Ground
VSS_SMPS_1V35 to Battery Ground
LX_1V8 to Inductor
LX_1V35 to Inductor
L1 to C4 Track
L2 to C7 Track
C4 to GND
C7 to GND
VBAT to Battery and C2 should be <1
Ω
from battery
VCHG to charger connector and C1
VDD_DIG to Ground
Ensure good low impedance ground return path through GND plane
for SMPSU current from C4 to VSS_SMPS_1V8 and C7 to VSS_SMPS_1V35
Ensure routing from L2 to ball K3 and from L2 to C8/C9 and ball C2 are kept separate
CSR recommends low Rdc inductors (<0.5
Ω
) for L1 and L2 for optimum power efficiency
For example Taiyo Yuden CB2012T4R7M
Suggest analogue and digital grounds are separated if possible
and star connected near VSS_AUDIO as shown
Ensure analogue tracks stay over Analogue ground as much as possible
G
R
EEN
D103
Li+ CELL
VBAT
3.7V
CON101
1V8
VBAT
1V8
1V8
F2
S102
F3
S101
F4
S100
RE
D
D102
BLU
E
D101
1V8
1V8
VOL-
S104
VOL+
S103
LE
D
_
0
LE
D
_
1
LE
D
_
2
10k
THERM100
AIO_0
VBUS
GND
5
ID
4
D+
3
D-
2
VBUS
1
GND
6
GND
7
USB MINI-B
CON100
USB_P
USB_N
PIO_5
3
1
2
BCX51
Q100
VBUS
1%
400mR
R104
CHG_EXT
VBAT_SENSE
VBAT
BAT54C
D100
VBUS
CE
1
SO/SIO1
2
WP/SIO2
3
VSS
4
SI/SIO0
5
SCK
6
HOLD/SIO3
7
VDD
8
U100
SPI Flash
1V8_SMPS
10n
C101
Optional Ancilliary Circuits
Optional Fast Charge
400m
Ω
= 500mA
USB / Charger Interface
Lithium Polymer Battery
(Built-in Battery Protection)
Battery Temperature Sensor
Typical LEDs and Buttons
Optional 1 x SPI Flash Memory
Connect VBAT_SENSE to VBAT
If Not Using This Circuit
9k1
R100
220R
R101
330R
R102
330R
R103
PIO_12
PIO_10
PIO_11
PIO_13
PIO
_
n
PIO
_
n
PIO
_
n
PIO
_
n
PIO
_
n
PIO_n (odd)
Digital
Mic(s)
PIO_n (even)
CLOCK
DATA
1V8_SMPS
4u7
C105
220mR
R108
1V8_SMPS
1V8_SMPS
10n
C100
Optional I
2
C EEPROM Memory
PIO_11
PIO_10
24AAxxx
VCC
8
VSS
4
A2
3
SCL
6
A1
2
A0
1
WP
7
SDA
5
U101
PIO_12
2k2
R107
2k2
R106
2k2
R105
Size of EEPROM Depends on Voice Prompt Requirements
PIO[6]
RST#
XTAL_IN
XTAL_OUT
AIO[0]
PIO[29]/LED[0]
PIO[30]/LED[1]
PIO[31]/LED[2]
USB_P
USB_N
PIO[12] / QSPI_FLASH_CS# / I2C_WP
PIO[10] / QSPI_FLASH_CLK / I2C_SCL
PIO[11] / QSPI_IO[0] / I2C_SDA
PIO[13] / QSPI_IO[1]
PIO[14] / UART_RX
PIO[15] / UART_TX
PIO[16] / UART_RTS
PIO[17] / UART_CTS
PIO[18]
SPI_PCM#
PIO[2]/PCM1_IN/SPI_MOSI
PIO[3]/PCM1_OUT/SPI_MISO
PIO[4]/PCM1_SYNC/SPI_CS#
PIO[5]/PCM1_CLK/SPI_CLK
PIO[7]
PIO[9]
PIO[1]
PIO[8]
PIO[0]
PIO[19]
PIO[20]
PIO[21]
LED Outputs
PIO / PCM1 / Debug SPI / I
2
S
PIO / Serial Flash / I
2
C
PIO / UART
Analogue Input / Output
USB (12Mbps)
Reset
SPI / PCM# High For SPI. Low For All Other Functions
Advance Information
This material is subject to CSR's non-disclosure agreement
© Cambridge Silicon Radio Limited 2011
Page 73 of 110
CS-209182-DSP1
C
SR8640 BGA
Data Sheet
