LTC4088_15 Datasheet, PDF (1/24 Pages) Linear Technology – High Efficiency Battery Charger/USB Power Manager

LTC4088
High Efficiency Battery
Charger/USB Power Manager
Features
n _{Switching Regulator Makes Optimal Use of Limited}
Power Available from USB Port to Charge Battery
and Power Application
n _{180mΩ Internal Ideal Diode Plus Optional External}
Ideal Diode Controller Seamlessly Provides Low
Loss Power Path When Input Power is Limited or
Unavailable
n _{Full Featured Li-Ion/Polymer Battery Charger}
n _{VBUS Operating Range: 4.25V to 5.5V (7V Absolute}
Maximum—Transient)
n _{1.2A Maximum Input Current Limit}
n _{1.5A Maximum Charge Current with Thermal Limiting}
n _{Bat-Track™ Adaptive Output Control}
n _{Slew Control Reduces Switching EMI}
n _{Low Profile (0.75mm) 14-Lead 4mm × 3mm DFN}
Package
Applications
n _{Media Players}
n _{Digital Cameras}
n _GPS
n _PDAs
n _{Smart Phones}
Description
The LTC^®4088 is a high efficiency USB PowerPath™
controller and Li-Ion/Polymer battery charger. It includes
a synchronous switching input regulator, a full-featured
battery charger and an ideal diode. Designed specifically
for USB applications, the LTC4088’s switching regulator
automatically limits its input current to either 100mA,
500mA or 1A for wall-powered applications via logic
control.
The switching input stage provides power to V_OUT where
power sharing between the application circuit and the
battery charger is managed. Unlike linear PowerPath
controllers, the LTC4088’s switching input stage can use
nearly all of the 0.5W or 2.5W available from the USB port
with minimal power dissipation. This feature allows the
LTC4088 to provide more power to the application and
eases thermal issues in space-constrained applications.
An ideal diode ensures that system power is available
from the battery when the input current limit is reached
or if the USB or wall supply is removed.
The LTC4088 is available in the low profile 14-lead 4mm
× 3mm × 0.75mm DFN surface mount package.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
PowerPath, Bat-Track and ThinSOT are trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners. Protected by U.S. Patents, including
6522118.
Typical Application
High Efficiency Battery Charger/USB Power Manager
WALL
3.3µH
USB
10µF
3.3V
1µF
0.1µF
V_BUS
D0
D1
D2
CHRG
LDO3V3
CLPROG
SW
LTC4088
PROG C/X GND
V_OUT
GATE
BAT
NTC
8.2Ω
2.94k
499Ω
+
Li-Ion
SYSTEM
LOAD
10µF
4088 TA01a
Switching Regulator Efficiency to
System Load (P_OUT/P_BUS)
100
90
80
70 ^{BAT = 4.2V}
60
BAT = 3.3V
50
40
30
20
10
0
0.01
V_BUS = 5V
I_BAT = 0mA
10x MODE
0.1
I_OUT (A)
1
4088 TA01b
4088fb
1