Charging Circuit - LG KP500 Service Manual

3.13 Charging circuit

ISL9221 accepts two power inputs, normally one from a USB (Universal Serial Bus) port and the other
from a desktop cradle.
The ISL9221 features 28V and 7V maximum voltages for the cradle and the USB inputs respectively.
Due to the 28V rating for the cradle input, low-cost, large output tolerance adapters can be used
safely.
VIO_2V62
4 R 7 2 4 R 6 2
0 1 K 0 0 1 K 0
P _ R P
C H G E _ O C
C H _ G N E
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
OVP Charging IC
VBUS_USB
VCHG U401
1
VDC
2
VUSB
TP400
3
_PPR
4
_CHG
TP401
5
_EN
6
IMIN
ISL9221
4 R 0 3 4 R 1 3
4 C 9 3
EUSY0351601
u 1
0 1 K 0 . 5 K 6
1 ( ) %
Figure 19 Charging circuit
3. TECHNICAL BRIEF
13
PGND
12
VDC_BYP
11
BAT
10
USB_BYP
9
IVDC
8
GND
7
IUSB
4 R 3 3 4 R
2 K 0
D
1 ( ) %
4 R 2 3 1 K 5
- 51 -
VBAT VBUS_OVP
VCHG_OVP
4 3 4 R 2 3
4 C 0 4 4 C 1 4 4 C 2 4
0 1 . F u 0 1 . F u 0 1 . F u
1 K 5
I N
h o m 4 : 0 5 m A
LGE Internal Use Only