LG GS290 Service Manual page 26

3. TECHNICAL BRIEF
Micro USB
VIO_2V62 VUSB VBAT
D2
BAT
R210 30
A4
USB_DM DN1
R209 30
A5
USB_DP U200
DP2
B3
UART_RX U1
TP203 A3
MAX14526EEWP+TCC6
UART_TX U2
A1
MIC
D4
AUD1
D3
AUD2
A2
ISET
I2C_SCL
I2C_SDA
USW_INT
VIO_2V62
USW_DM
USW_DP
USW_ID
Figure 21.U-USB Connector circuit
The MAX14526 is a complete solution for multiplexing USB, UART and audio on a single mini/micro USB
connector. It contains an internal method for determining the device connected and uses an I2C bus for
control.
The switch will multiplex multiple inputs (USB, UART,Microphone, Stereo and Audio) on one mini/microUSB
connector. The USB and UART inputs support Hi-Speed USB and the audio inputs feature negative rail signal
operation allowing simple dc coupled headset speakers. The VB connection is protected against faults up to 28
volts. There is an internal device detection method which uses the USB ID signal pin and the voltage on VBUS.
Each accessory will have a unique detection based on resistor values and voltage on VBUS. The host
microprocessor uses I2C to control the switch position as well as read the results of the accessory detection.
The MAX14526 will also detect USB chargers including dedicated chargers (D+/D- shorted) and high power
host/hub chargers.
LGE Internal Use Only - 52 -
V_BUS
D5
VB
C5
COMN1 USW_DM
B5
USW_DP
COMP2
FB200
B4
UID USW_ID
RPWRON_EN
R200
B1
RES
2.2K
D1
CAP
C4
GND
C3
IC
C206
2.2u C213
DNI
R218
10K
V_BUS
CN200
6
8
10
12
14
1
SC200
2
1 2
3
4
5
7
9
C221 C220
11
DNI 22p
13
15
GU073-5P-SD-E1500
Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
*RF Block Diagram
*RF Block Diagram
Mobile Switch
Figure 22 GS290 RF part Block Diagram
Copyright © 2010 LG Electronics. Inc. All right reserved. - 53 -
Only for training and service purposes
3. TECHNICAL BRIEF
ANT
ANT
FEM
PAM(SKY77344)
LGE Internal Use Only