Datasheet

LTC4063
17
4063fc
applicaTions inForMaTion
USB and Wall Adapter Power
The LTC4063 allows charging from both a wall adapter
and a USB port. Figure 9 shows how to combine wall
adapter and USB power inputs. A P-channel MOSFET,
MP1, is used to prevent back conducting into the USB
port when a wall adapter is present and a Schottky diode,
D1, is used to prevent USB power loss through the 1k
pull-down resistor.
Most wall adapters can supply more current than the 500mA
limited USB port. Therefore, an N-channel MOSFET, MN1,
and an extra 3.3k program resistor are used to increase
the charge current to 800mA when the wall adapter is
present.
+
V
CC
D1
PROG
IDETGND
3.3k
2k
MN1
5V WALL
ADAPTER
I
CHG
= 800mA
USB POWER
I
CHG
= 500mA
MP1
4063 F09
BAT
LTC4063
1.25k
Li-Ion
BATTERY
SYSTEM
LOAD
1k
Figure 9. Combining Wall Adapter and USB Power
Typical applicaTion
Full-Featured Li-Ion Charger with 2.5V Regulated Output
(Using Charge Time Termination)
+
CHRG
TIMER
PROG
IDET
6
7
9
8
BAT
OUT
FB
1
2
3
LTC4063
GND
340k
800mA
160k
11
625Ω
1.25k
1k
10
2.2µF
1µF
0.1µF
V
IN
5V
4063 TA02
V
OUT
2.5V
SINGLE CELL
Li-Ion BATTERY
V
CC