Functional Diagram
Functional Diagrams
Detailed Block Diagram
BUFFER (8B)
BUFFER (8B)
1-WIRE ROM FUNCTION & DEVICE FUNCTION COMMANDS
1-Wire
ROM
FUNCTION
AND
DEVICE
FUNCTION
COMMANDS
CRC-16 CHECK
CRC-16
CHECK
1-Wire Input/Output A. Accessible when the TOKEN pin is logic low. This pin can also be configured in a logic pass-through mode to IOB pin. IOA parasite power required for CD/PIOC pin operation.
IOA
IOA
1-Wire Input/Output B. This pin can also be configured in a logic pass-through mode to IOA pin.
IOB
IOB
GPIO CONTROL
GPIO
CONTROL
DS2488
DS2488
Charger Disable (Default) or General-Purpose Input/Output (SEL bit is set to one). Charger disable is floating (i.e., non-conducting) when the IOA pin is nominally below 4V. Otherwise, charger disable is actively low to enable the charger through a transistor when IOA is above 4V.
CD/PIOC
CD/PIOC
LOW-DROPOUT REGULATOR
LOW-DROPOUT
REGULATOR
VDD
V
DD
IN
IN
OUT
OUT
VREG
V
REG
VREG
V
REG
PIOC_OUT
PIOC_OUT
I1
I
1
I0
I
0
Voltage Low. This is the low-power supply input. Needed for IOB, PIOA, PIOB, and TOKEN pin operation.
VL
V
L
CMP
CMP
PIOC_IN
PIOC_IN
VDD
V
DD
SW1
SW1
Token. This pin indicates which 1-Wire side gets the communication token. Logic low stands for IOA side, while logic high for IOB side. It outputs a low-frequency clock (TOKF) while in pass-through mode.
TOKEN
TOKEN
REGISTERS
REGISTERS
STATUS
STATUS
CONFIG
CONFIG
PIO
PIO
VREG
V
REG
General-Purpose Input/Output A.
PIOA
PIOA
General-Purpose Input/Output B.
PIOB
PIOB
64-BIT ROM
64-BIT
ROM
VREG
V
REG
500K
500kΩ
TIMER
TIMER
CHARGE_CAP
CHARGE_CAP
UNLOAD_CAP
UNLOAD_CAP
FLOAT_DETECT
FLOAT_DETECT
5M
5MΩ
Q1
Q1
N
N
Voltage Low. This is the low-power supply input. Needed for IOB, PIOA, PIOB, and TOKEN pin operation.
VL
V
L
PTM
PTM
VDD
V
DD
GPIO CONTROL
GPIO
CONTROL
VDD
V
DD
VDD
V
DD
VDD
V
DD
Voltage Low. This is the low-power supply input. Needed for IOB, PIOA, PIOB, and TOKEN pin operation.
VL
V
L
Voltage Low. This is the low-power supply input. Needed for IOB, PIOA, PIOB, and TOKEN pin operation.
VL
V
L
Voltage Low. This is the low-power supply input. Needed for IOB, PIOA, PIOB, and TOKEN pin operation.
VL
V
L
Voltage Low. This is the low-power supply input. Needed for IOB, PIOA, PIOB, and TOKEN pin operation.
VL
V
L
VREG
V
REG
VREG
V
REG
Voltage Low. This is the low-power supply input. Needed for IOB, PIOA, PIOB, and TOKEN pin operation.
VL
V
L
VDD
V
DD
IOA PARASITE POWER CAP
IOA PARASITE
POWER CAP
WEAK_PULLDOWN
WEAK_PULLDOWN
TWS Application Circuit Using UART Peripherals for 1-Wire Communication
BLUETOOTH EARBUD (RIGHT)
BLUETOOTH EARBUD (RIGHT)
AUDIO
AUDIO
MIC
MIC
BLUETOOTH AUDIO SoC
BLUETOOTH AUDIO
SoC
UART
UART
TX
TX
RX
RX
1-Wire Input/Output A. Accessible when the TOKEN pin is logic low. This pin can also be configured in a logic pass-through mode to IOB pin. IOA parasite power required for CD/PIOC pin operation.
IOA
IOA
1-Wire Input/Output B. This pin can also be configured in a logic pass-through mode to IOA pin.
IOB
IOB
Token. This pin indicates which 1-Wire side gets the communication token. Logic low stands for IOA side, while logic high for IOB side. It outputs a low-frequency clock (TOKF) while in pass-through mode.
TOKEN
TOKEN
BATTERY CHARGER
BATTERY
CHARGER
DS2488
DS2488
1.8V
1.8V
1uF
1uF
Charger Disable (Default) or General-Purpose Input/Output (SEL bit is set to one). Charger disable is floating (i.e., non-conducting) when the IOA pin is nominally below 4V. Otherwise, charger disable is actively low to enable the charger through a transistor when IOA is above 4V.
CD/PIOC
CD/PIOC
Voltage Low. This is the low-power supply input. Needed for IOB, PIOA, PIOB, and TOKEN pin operation.
VL
V
L
MCU
MCU
TEMPERATURE/ IN-EAR DETECT
TEMPERATURE/
IN
-EAR DETECT
I2C
I2C
LI-ION BATTERY (60-150mA/h)
LI-ION BATTERY
(60
-150mA/h)
HEART RATE
HEART RATE
PWR
PWR
LDO/DC-DC
LDO/DC-DC
1.8V
1.8V
General-Purpose Input/Output B.
PIOB
PIOB
CH R/L
CH R/L
General-Purpose Input/Output A.
PIOA
PIOA
GPIO1
GPIO1
GPIO2
GPIO2
GPIO3
GPIO3
IRQ
IRQ
UART
UART
MCU
MCU
TX
TX
RX
RX
3.3V
3.3V
EN
EN
CHG/IO
CHG/IO
Ground.
GND
GND
CHARGING BOX
CHARGING BOX
BATTERY CHARGER
BATTERY
CHARGER
LI-ION BATTERY (1000-2000mA/h)
Li+ BATTERY
(1000mAh TO 2000mAh)
LID DETECT
LID DETECT
LEFT EARBUD BATT STATUS
LEFT EARBUD
BATT STATUS
RIGHT EARBUD BATT STATUS
RIGHT EARBUD
BATT STATUS
5V DC-DC BOOST
5V DC-DC BOOST
LDO/DC-DC
LDO/
DC
-DC
ADC
ADC
USB
USB
PWR
PWR
USB DATA
USB DATA
3.3V
3.3V
PWR
PWR
CH
CH
BATTERY
BATTERY
GPIO
GPIO
BT PAIRING
BLUETOOTH PAIRING
IRQ
IRQ
I2C
I
2
C
200k
200kΩ
BLUETOOTH EARBUD (LEFT)
BLUETOOTH EARBUD (LEFT)
AUDIO
AUDIO
MIC
MIC
BLUETOOTH AUDIO SoC
BLUETOOTH AUDIO
SoC
UART
UART
TX
TX
RX
RX
1-Wire Input/Output A. Accessible when the TOKEN pin is logic low. This pin can also be configured in a logic pass-through mode to IOB pin. IOA parasite power required for CD/PIOC pin operation.
IOA
IOA
1-Wire Input/Output B. This pin can also be configured in a logic pass-through mode to IOA pin.
IOB
IOB
Token. This pin indicates which 1-Wire side gets the communication token. Logic low stands for IOA side, while logic high for IOB side. It outputs a low-frequency clock (TOKF) while in pass-through mode.
TOKEN
TOKEN
BATTERY CHARGER
BATTERY
CHARGER
DS2488
DS2488
1.8V
1.8V
1uF
1μF
Charger Disable (Default) or General-Purpose Input/Output (SEL bit is set to one). Charger disable is floating (i.e., non-conducting) when the IOA pin is nominally below 4V. Otherwise, charger disable is actively low to enable the charger through a transistor when IOA is above 4V.
CD/PIOC
CD/PIOC
Voltage Low. This is the low-power supply input. Needed for IOB, PIOA, PIOB, and TOKEN pin operation.
VL
V
L
MCU
MCU
TEMPERATURE/ IN-EAR DETECT
TEMPERATURE/
IN
-EAR DETECT
I2C
I
2
C
LI-ION BATTERY (60-150mA/h)
Li+ BATTERY
(60mAh TO 150mAh)
HEART RATE
HEART RATE
PWR
PWR
LDO/DC-DC
LDO/DC-DC
1.8V
1.8V
General-Purpose Input/Output B.
PIOB
PIOB
CH R/L
CH R/L
General-Purpose Input/Output A.
PIOA
PIOA
UART MODE
UART MODE
GPIO1
GPIO1
GPIO2
GPIO2
GPIO3
GPIO3
IRQ
IRQ
