LTC4053-4.2_15 Datasheet, PDF (1/16 Pages) Linear Technology – USB Compatible Lithium-Ion Battery Charger with Thermal Regulation

LTC4053-4.2
USB Compatible
Lithium-Ion Battery Charger
with Thermal Regulation
FEATURES
■ _{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 (0.75m_Um) 3mm × 3mm DFN packages
APPLICATIO S
■ _{Cellular Telephones}
■ _{Handheld Computers}
■ _{Charging Docks and Cradles}
■ _{MP3 Players}
■ _{Digital Cameras}
DESCRIPTIO
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.
TYPICAL APPLICATIO
USB Powered Standalone Li-Ion Charger
USB PORT
4.35V TO 5.5V
2
V_CC
9
BAT
LTC4053-4.2
SYSTEM
+
LOAD
Li-Ion
BATTERY
4
8
TIMER SHDN
4.7µF
GND NTC PROG
5 6 7 ^3.74k
0.1µF
15k
SUSPEND
USB CONTROL
µC
100mA/
500mA
4053TA01
Charge Current vs Input Voltage
600
500 ^{VBAT = 3.95V}
T_A = 25°C
R_PROG = 3k
400
V_BAT = 4.05V
300
200
V_BAT = 4.15V
100
0
4.0
4.5
5.0
V_CC (V)
5.5
4053 G04
4053fa
1