Only For Training And Service Purposes - LG GD310 Service Manual

3. Technical Brief
Li-ION
Battery
Charger
Battery
1uF
D-
USB 2.0
D+
Hi-Speed
RX
UART
TX
Audio Mic
CODEC
Left
MAX9877
Right
Connect to ground or leave
unconnected to set default startup
to USB. Connect to VBAT with a
300K resistor for UART startup
I2C_Clock
I2C_Data
MicroController
Interrupt
LGE Internal Use Only
BAT
DN1
DP2
100K
VCCINT
U1
U2
MIC
22pF
AUD1
22pF
AUD2
22pF
IC
Latch
D Q
0.4V
ISET
0.4V
IOVcc
Figure 24. MUIC Typical Application Circuit
VCCINT
VB
3.7V LDO
Ideal Diodes
3.5V
COMN1
COMP2
USB
Charger
Detection
UID
ADC
RES
100K
800K
100K
Control
CAP
UID LDO
VCCINT
GND
- 54 - Copyright © 2009 LG Electronics. Inc. All right reserved.
1uF
>30V
22pF
>30V
VBUS
D-
D+
ID
22pF
GND
Adjust this resistor value for the
bias current required by the
3.3K
headset microphone – ideal value
should give Vmic_dc of 1.1V with
an average headset (300uA dc bias
current)
2.2uF
X5R or
X7R

Only for training and service purposes