LTC4053-4.2
USB Compatible
Lithium-Ion Battery Charger
with Thermal Regulation
FEATURES
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DESCRIPTIO
Charges Single-Cell Li-Ion Batteries Directly from
USB Port
Thermal Regulation Maximizes Charge Rate
without Risk of Overheating*
Programmable Charge Current with
±7%
Accuracy
Low Dropout Operation
No External MOSFET, Sense Resistor or Blocking
Diode Required
Programmable Charge Termination Timer
Preset Charge Voltage with
±1%
Accuracy
C/10 Charge Current Detection Output
AC Present Logic Output
25µA Supply Current in Shutdown Mode
Automatic Recharge
Charge Current Monitor Useful for Gas Gauging
Thermistor Input for Temperature Qualified Charging
Available in 10-pin thermally enhanced MSOP and
low profile (0.75mm) 3mm
×
3mm DFN packages
The LTC
®
4053 is a standalone linear charger for lithium-
ion batteries that can be powered directly from a USB port.
The IC contains an on-chip power MOSFET and eliminates
the need for an external sense resistor and blocking diode.
Thermal regulation automatically adjusts charge current
to limit die temperature during high power or high ambient
temperature conditions. This feature protects the end
product and the LTC4053 from thermal stress while the IC
charges the battery at maximum rate without interruption.
The charge current and charge time can be set externally
with a single resistor and capacitor, respectively. When
the input supply (wall adapter or USB supply) is removed,
the LTC4053 automatically enters a low current sleep
mode, dropping the battery drain current to less than 5µA.
The LTC4053 also includes NTC temperature sensing,
C/10 detection circuitry, AC present logic, low battery
charge conditioning (trickle charging) and shutdown (25µA
supply current).
The LTC4053 is available in 10-pin thermally enhanced
MSOP and low profile (0.75mm) DFN packages.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Protected by U.S. Patents including 6522118, 6700364.
APPLICATIO S
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Cellular Telephones
Handheld Computers
Charging Docks and Cradles
MP3 Players
Digital Cameras
TYPICAL APPLICATIO
USB PORT
4.35V TO 5.5V
2
V
CC
BAT
Charge Current vs Input Voltage
600
500
400
I
BAT
(mA)
USB Powered Standalone Li-Ion Charger
9
SYSTEM
LOAD
Li-Ion
BATTERY
V
BAT
= 3.95V
+
LTC4053-4.2
4
4.7µF
8
300
200
TIMER
SHDN
SUSPEND
3.74k
USB CONTROL
µC
100mA/
500mA
GND NTC PROG
5
6
7
15k
V
BAT
= 4.15V
100
0
0.1µF
4.0
4053TA01
U
T
A
= 25°C
R
PROG
= 3k
V
BAT
= 4.05V
4.5
V
CC
(V)
4053 G04
U
U
5.0
5.5
4053fa
1
LINER [ LINEAR TECHNOLOGY ]
