LTC1732-4 Datasheet | Linear Technology

.. LTC1732-4/LTC1732-4.2 Lithium-Ion Linear Battery Charger Controller Features s s s s s s s s s s DESCRIPTIO s s s s s plete Linear Charger Controller for 1-Cell Lithium-Ion Batteries Preset Charge Voltage with 1% Accuracy Programmable Charge Current C/10 Charge Current Detection Output Programmable Charge Termination Timer Small, Thin 10-Pin MSOP Package Select Pin Charges 4.1V or 4.2V Cells (LTC1732-4) Input Supply (Wall Adapter) Detection Output 4.5V to 12V Input Voltage Range Automatic Sleep Mode When Input Supply is Removed (Only 7µA Battery Drain) Automatic Trickle Charge of Low Voltage Cells Programmable for Constant-Current-Only Mode Battery Insertion Detect 4.05V Recharge Threshold for 4.2V Cells (LTC1732-4.2) 3.8V Recharge Threshold for 4.1V or 4.2V Cells (LTC1732-4) The LTC ®1732 is a plete constant-current/constantvoltage linear charger controller for lithium-ion (Li-Ion) batteries. Nickel-cadmium (Ni Cd) and nickel metalhydride (Ni MH) batteries can also be charged with constant current using external termination. Charge current can be programmed with 7% (max) accuracy using external sense and program resistors. An internal resistor divider and precision reference set the final float voltage with 1% accuracy. The SEL pin allows users to charge either 4.1V or 4.2V cells. When the input supply is removed, the LTC1732 automatically enters a low current sleep mode, dropping the battery drain current to 7µA. An internal parator detects the end-of-charge (C/10) condition while a programmable timer, using an external capacitor, sets the total charge time. Fully discharged cells are automatically trickle charged at 10% of the programmed current until cell voltage exceeds 2.457V. The LTC1732 begins a new charge cycle when a discharged battery is connected to the charger or when the input power is applied. In addition, if the battery remains connected to the charger and the cell voltage drops below 3.8V for the LTC1732-4 or...