LTC3455 Datasheet, PDF (9/24 Pages) Linear Technology – Dual DC/DC Converter with USB Power Manager and Li-Ion Battery Charger

BLOCK DIAGRA
LTC3455
USB 5V
USB
8
1Ω
4.7µF
USB
CONTROLLER
SUSPEND
6
USBHP
5
V_MAX
1k
0.1µF
CHRG
4
TIMER
3
PROG
2
2.49k
GND
25
V_BAT
3.3V to 4.2V
4.7µF
2.43M
V_{BAT 9}
AI
16
806k
USB POWER MANAGER
1 1000
– REF
+
R
4R
3.9V –
+
BATTERY CHARGER
1 1000
– 1.23V
+
2.41R
+
CHARGE
CONTROL
R
LBO
ON/OFF
AO
17
806k
1.8V
ON
24
PBSTAT
23
806k
1.8V
–
+ 0.8V
V_BAT +
UVLO
3.0V –
µC
PWRON
22
ON2
19
RST
20
MODE
21
HSON
15
200ms RESET PULSE
BURST MODE ENABLE
EXTPWR
EXTPWR
3.32k
+
WALLFB
11
– 1.23V
1.24k
BATTERY PMOS SWITCH
10 ^VMAX
WALL 5V
1Ω
1µF
V_MAX
10µF
SWITCHER 1
PWM
DRIVER
ENABLE
–
+ 0.8V
SW1 ^4.7µH
7
FB1
1
100k
80.6k
1.8V
10µF
SWITCHER 2
PWM
DRIVER
ENABLE
–
+ 0.8V
SW2 ^4.7µH
12
FB2
18
249k
80.6k
HOT SWAP
ENABLE
HSI
13
HSO
14
3455 BD01
3.3V
10µF
3.3V, HS
1µF
3455f
9