LTC3550-1_15 Datasheet, PDF (22/24 Pages) Linear Technology – Dual Input USB/AC Adapter Li-Ion Battery Charger with 600mA Buck Converter

LTC3550-1
APPLICATIO S I FOR ATIO
WALL
ADAPTER
USB
POWER
1µF
LTC3550-1
RUN
SW
DCIN V_OUT
USBIN V_CC
1µF
IUSB BAT
2.1k
1%
IDC ITERM
GND
1.24k
1%
* MURATA LQH32CN2R2M33
** TAIYO YUDEN JMK316BJ106ML
† _{TAIYO YUDEN LMK212BJ475MG}
2.2µH*
800mA (WALL)
475mA (USB)
V_OUT
1.875V
600mA
10µF**
CER
1.24k
1%
4.7µF^†
+
4.2V
SINGLE-
CELL Li-Ion
BATTERY
3550-1 F07a
Figure 7a. Design Example Circuit
100
V_CC = 2.7V
90
V_CC = 4.2V
80
70
V_CC = 3.6V
60
50
0.1
1
10
100
I_LOAD (mA)
1000
35501 F07b
Figure 7b. Buck Regulator Efficiency vs Output Current
TYPICAL APPLICATIO S
WALL
ADAPTER
USB
POWER
Full Featured Dual Input Charger Plus Step-Down Converter
1µF
2.1k
1%
LTC3550-1
BAT
DCIN
USBIN
1k
PWR
1µF
1k
CHRG
1.24k
1%
IUSB
V_CC
IDC
SW
ITERM
V_OUT
1k
GND
1%
2.2µH
800mA (WALL)
475mA (USB)
4.7µF
+
4.2V
SINGLE-CELL
Li-Ion BATTERY
10µF
CER
V_OUT
1.875V
600mA
3550-1 TA03
22
35501f