LTC3553_15 Datasheet, PDF (1/36 Pages) Linear Technology – Micropower USB Power Manager With Li-Ion Charger, LDO and Buck Regulator

LTC3553
Features
Micropower USB Power
Manager With Li-Ion Charger,
LDO and Buck Regulator
Description
n _{12μA Standby Mode Quiescent Current (All Outputs On)}
n _{Seamless Transition Between Input Power Sources:}
Li-Ion/Polymer Battery and USB
n _{240mΩ Internal Ideal Diode Provides Low Loss}
PowerPath™
n _{High Efficiency 200mA Buck Regulator}
n _{150mA Low Dropout (LDO) Linear Regulator}
n _{Pushbutton On/Off Control With System Reset}
n _{Full Featured Li-Ion/Polymer Battery Charger}
n _{Programmable Charge Current With Thermal Limiting}
n _{Instant-On Operation With Discharged Battery}
n _{3mm × 3mm × 0.75mm 20-Pin QFN Package}
Applications
n _{USB-Based Handheld Products}
n _{Portable Li-Ion/Polymer Based Electronic Devices}
n _{Wearable Electronics}
n _{Low Power Medical Devices}
The LTC^®3553 is a micropower, highly integrated power
management and battery charger IC for single-cell
Li-Ion/Polymer battery applications. It includes a
PowerPath manager with automatic load prioritization,
a battery charger, an ideal diode and numerous internal
protection features. Designed specifically for USB applica-
tions, the LTC3553 power manager automatically limits
input current to a maximum of either 100mA or 500mA.
Battery charge current is automatically reduced such that
the sum of the load current and the charge current does
not exceed the selected input current limit. The LTC3553
also includes a synchronous buck regulator, a low dropout
linear regulator (LDO), and a pushbutton controller. With
all supplies enabled in standby mode, the quiescent cur-
rent drawn from the battery is only 12μA. The LTC3553 is
available in a 3mm × 3mm × 0.75mm 20-pin QFN package.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
PowerPath, Hot Swap and Bat-Track are trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners. Protected by U.S. Patents, including
6522118, 6700364, 5481178, 6304066, 6570372, 6580258, 7511390 and other patents pending.
Typical Application
4.35V TO 5.5V
USB INPUT
100k
10µF
100k T
1.87k
V_BUS
V_OUT
10µF
NTC LTC3553 CHRG
PROG
BAT
+ Li-Ion
BATTERY
SYSTEM
LOAD
SEQ
BVIN
V_INLDO
2.2µF
DIGITAL
CONTROL
ON/OFF
HPWR
SUSP
LDO_ON
BUCK_ON
STBY
PBSTAT
ON
LDO
LDO_FB
2.05M
3.3V
150mA
4.7µF
649k
SW
BUCK_FB
3553 TA01a
10µH
10pF
332k
649k
1.2V
200mA
10µF
Battery Drain Current
vs Temperature
18
V_BAT = 3.8V
16 ^{STBY = 3.8V}
REGULATORS LOAD = 0mA
14
BUCK AND LDO ON
12
10
ONLY LDO ON
8
ONLY BUCK ON
6
BUCK AND LDO OFF
4
2
HARD RESET
0
–50 –30 –10 10 30 50 70 90 110 130
TEMPERATURE (°C)
3553 TA01b
3553fc
1