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3. TECHNICAL BRIEF
- 46 -
Copyright © 2012 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
LG530G
30/87
3.6.3 Mini ABB
Figure 3-6-2. RT8966 Function Block Diagram
The RT8966A is an analog subsystem which includes a linear charger, 4 LDOs, a 4-CH current source, and a
multiplexer for USB, UART, microphone, stereo and audio on a single mini/micro USB connector.
The RT8966 adopts an I2C bus for control and uses an internal method to determine the connected device. The USB
input provides high speed USB connection. The audio inputs feature negative rail signal operation to realize simple
DC coupled headset speakers. The RT8966 provides an internal device detection method by using the USB ID signal
pin and the VBUS voltage. The resistor values and VBUS voltage determine the unique detection method of each
accessory. The host microprocessor adopts I2C to control the switch position and read the results of the accessory
detection. The RT8966 can also detect USB chargers, including dedicated chargers (D+/ D-shorted) and high, power,
host/hub chargers. The RT8966 has a linear charger with maximum 1A current capability. The charging current and
end of charge current can be controlled by I2C interface. It also provides a 50mA LDO to support the power of the
peripheral circuit. In factory mode, the RT8966A provides 4.2V/2.3A power to support system operation.
VIN
VBUS
COMN1
VCCINT
COMP2
UID
MIC
AUD2
AUD1
U2
LDO
LDO4
OUT4
OUT3
OUT2
OUT1
LED1 LED2 LED3 LED4
LDO3
LDO2
LDO1
DAC
UPIC
LDO
USB
Charger
Detection
Charger
Block
U1
DN1
EXPDET
VBAT
DP2
DSS
GND
SCL SDA INT
RES
Control
ADC
CAP
2.3V
100k
100k
100k
1.8V
200k
800k
300k
MR-COMP
SE-COMP
V
UVP
V
CCINT
620
3.6.3 Mini ABB