The LTC®
4053 is a standalone linear charger for lithiumion 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.

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