LTC4088-2_15 Datasheet, PDF (1/24 Pages) Linear Technology – High Efficiency Battery Charger/USB Power Manager with Regulated Output Voltage

LTC4088-1/LTC4088-2
High Efficiency Battery
Charger/USB Power Manager
with Regulated Output Voltage
Features
Description
n _{Switching Regulator Makes Optimal Use of Limited The LTC}^®_{4088-1/LTC4088-2 is a high efficiency USB}
Power Available from USB Port to Charge Battery
PowerPath™ controller and Li-Ion/Polymer battery char-
and Power Application
ger. It includes a synchronous switching input regulator,
n _{180mΩ Internal Ideal Diode Plus External Ideal Diode a full-featured battery charger and an ideal diode. De-}
Controller Seamlessly Provide Low Loss Power Path signed specifically for USB applications, the LTC4088-1/
When Input Power is Limited or Unavailable
LTC4088-2’s switching regulator automatically limits its
n _{Automatic Charge Current Reduction Maintains 3.6V input current to either 100mA, 500mA or 1A via logic}
Minimum V_OUT
n _{Full Featured Li-Ion/Polymer Battery Charger}
control. The LTC4088-1 powers-up with the charger off;
the LTC4088-2 powers-up with the charger on.
n
n
n
n
n
n
V_BUS Operating Range: 4.25V to 5.5V (7V Absolute
Maximum—Transient)
1.2A Maximum Input Current Limit
1.5A Maximum Charge Current with Thermal Limiting
Bat-Track™ Adaptive Output Control
Slew Control Reduces Switching EMI
Low Profile (0.75mm) 14-Lead 4mm × 3mm DFN Package
The switching input stage provides power to V_OUT where
power sharing between the application circuit and the
battery charger is managed. Charge current is automati-
cally reduced to maintain a regulated 3.6V V_OUT during
low-battery conditions. As the battery is charged, V_OUT
tracks V_BAT for high efficiency charging. This feature al-
lows the LTC4088-1/LTC4088-2 to provide more power
Applications
n _{Media Players}
n _{Digital Cameras}
n _GPS
n _PDAs
to the application and eases thermal issues in 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.
n _{Smart Phones}
The LTC4088-1/LTC4088-2 is available in the low profile
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
PowerPath and Bat-Track are tradmearks of Linear Technology Corporation. All other trademarks
are the property of their respective owners. Protected by U.S. Patents, including 6522118.
14-Lead 4mm × 3mm × 0.75mm DFN surface mount
package.
Typical Application
High Efficiency Battery Charger/USB Power Manager
WALL
USB
10µF
3.3µH
V_BUS
D0
D1
D2
SW V_OUT
V_OUTS
LTC4088-1/LTC4088-2 ^GATE
CHRG
BAT
CLPROG PROG C/X GND NTC
8.2Ω
0.1µF
2.94k
499Ω
+
Li-Ion
SYSTEM
LOAD
10µF
408812 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
408812 TA01b
40881fc
1