3. TECHNICAL BRIEF
- 49 -
LGE Internal Use Only
Copyright © 011 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3.10 MiniABB (Battery Charger & MUIC) Interface
Figure 3-10-1 Mini ABB BLOCK
The LP8727 is designed to provide automatic multiplexing switches between Micro/Min USB connector and
USB, UART, and Audio paths in cellular phone applications, and it also contains a single-input Li-ion battery
charger and over-voltage protected LDO. Programming is handled via ans I2C compatible Serial Interface
allowing control of charger, multiplexing switches, and reading status information of the device.
The multiplexing switches on USB and UART support High-Speed USB and Audio inputs can be driven to
negative voltage rail. The LP8727 is compatible with USB charging specification rev 1.1 form USB IF.
The Li-ion charger requires few external components and integrates the Power FET. Charging is thermally
regulated to obtain the most efficient charging rate for a given ambient temperature. It has Over-Voltage
Protection (OVP) circuit at the charger input protects the PMU from input voltage up to +28V, eliminating the
need for and external protection circuitry.
An Over-voltage protected LDO which can supply up to 50mA is designed for powering up low voltage USB
transceiver or waking up a PMU(Power Management Unit)when an external power source(either USB VBUS or
wall adapter) is connected to the USB connector.
2.2K
R408
C402
0.1u
VUSB_CHG_IN
VUSB_CHG_IN
R401
47K
VDD_IO_1V8
VBAT
1u
C401
10K
R409
VDD_IO_1V8
FB403
1800
LP8727
U401
C5
D2
B5
D3
D1
E1
E2
E3
E5
E4
A1
C1
B1
A4
A5
A3
A2
D5
4
D
4
C
3
C
2
C
2
B
3
B
4
B
L
C
S
A
D
S
¬
¡
T
N
I
1
D
N
G
2
D
N
G
3
D
N
G
4
D
N
G
BATT2
DN
DP
U1
U2
AUD1
AUD2
MIC
VBUS1
VBUS2
D-
D+
ID
RES
DSS
EXPDET
CAP
BATT1
C412
1u
1u
C411
R406
DNI
R403
10
R404
10
USB_DP
USB_DM
UART_TX
MUIC_ACC_ID
UART_RX
VUSB_LDO_4V9
I2C_SDA
I2C_SCL
MUIC_IO_P
MUIC_IO_M
MUIC_INT_N