29
XW-NAV1-K
5
6
7
8
5
6
7
8
A
B
C
D
E
F
(2) Power supply for iPod
Overview
A battery charger of iPod has Current Limitter IC (IC1704).
Microcomputer detects overcurrent and stops suppling
power to iPod.
Ports on the system microcomputer to be
used for detection
Microcomputer (IC3001) pin 67 P2_3 IP_FAULT
This terminal detects "L", which detects overcurrent.
Microcomputer (IC3001) pin 68 P2_2 IP_PO
W
This terminal becomes "H", which supply power to iPod.
Operation of the protection circuits
W
hen electricity, flows 5
V
for iPod battery charger,
exceeds 700 mA, current Limiter IC detects overcurrent
and IP_FAULT becomes "L".
(Pin 3 of IC1704 becomes "L", which means overcurrent
flows.)
Processin
g
when protection circuit is detected
W
hen microcomputer detects IP_FAULT becoming "L", it
stops suppling power to iPod.
This will be maintained till it becomes Power O
N
from standby.
(3) USB power supply
Overview
USB power supply has High Side S
W
IC (IC4004).
W
hen
over-current flows, it stops supplying power to USB and
shows "Err" on LEM.
Ports on the system microcomputer to be
used for detection
MPEG IC (IC4001) pin 39 USB_FLAG
This terminal become "L", which detects overcurrent.
MPEG IC (IC4001) pin 18 USB_P_O
N
-L
This terminal become "L", which supply power to USB.
Operation of the protection circuits
for USB, exceeds overcurrent
. 550 mA, MAX. 1000 mA), High Side S
W
IC detects
overcurrent. In addition, USB_FLAG becomes "L".
(Pin 5 of IC4004 become "L", which shows overcurrent flows.)
Processin
g
when protection circuit is detected
W
hen MPEG IC detects USB_FLAG becoming "L", it makes
USB_P_O
N
-L terminal "H", stops suppling power to USB,
and shows "Err" on LEM.
Untill FU
N
CTIO
N
is changed and becomes USB mode again
or standby, this will be maintained.
IP_PO
W
IP_FAULT
www. xiaoyu163. com
QQ 376315150
9
9
2
8
9
4
2
9
8
TEL 13942296513
9
9
2
8
9
4
2
9
8
0
5
1
5
1
3
6
7
3
Q
Q
TEL 13942296513 QQ 376315150 892498299
TEL 13942296513 QQ 376315150 892498299