Monolithic Linear Lithium-Ion Battery Charger with Thermal Regulation

The LTC1733 is a standalone constant-current/constant-voltage linear charger for lithium-ion batteries with an on-chip power MOSFET. Internal thermal feedback regulates the charge current to limit die temperature during high power operation or high ambient temperature conditions. This feature allows the user to program a high charge current without risk of damaging the LTC1733 or the handheld product.

No external current sense resistor is needed and no blocking diode is required due to the internal MOSFET architecture. The charge current and charge time can be set externally with a single resistor and capacitor, respectively. When the input supply (wall adapter) is removed, the LTC1733 automatically enters a low current sleep mode, dropping the battery drain current to less than 5µA.

The LTC1733 also includes NTC temperature sensing, C/10 detection circuitry, AC present logic, 4.1V/4.2V pin selectability and low battery charge conditioning (trickle charging).

The LTC1733 is available in a 10-pin thermally enhanced MSOP package.

Applications

* Cellular Telephones

* Handheld Computers

* Digital Still Cameras

* Charging Docks and Cradles

* Complete Linear Charger for 1-Cell Lithium-Ion Batteries

* Thermal Regulation Maximizes Charging Rate without Risk of Overheating*

* No External MOSFET, Sense Resistor or Blocking Diode Required

* Up to 1.5A Charging Current

* Preset Charge Voltage with 1% Accuracy

* Programmable Charge Current with 7% Accuracy

* Programmable Charge Termination Timer

* Tiny Thermally Enhanced 10-Pin MSOP Package

* Charge Current Monitor Useful for Gas Gauging*

* C/10 Charge Current Detection Output

* Automatic Recharge

* Thermistor Input for Temperature Qualified Charging

* AC Present Logic Output

* 4.1V/4.2V Pin Selectable Output Voltage