LTC1734L

LTC1734L Lithium-Ion Linear Battery Charger in ThinSOT FEATURES s s s s s s DESCRIPTIO s s s s s Low Profile (1mm) ThinSOTTM Package Programmable Charge Current: 50mA to 180mA No Blocking Diode Required No Sense Resistor Required 1% Accurate Preset Voltage: 4.2V Charge Current Monitor Output for Charge Termination Automatic Sleep Mode with Input Supply Removal Manual Shutdown Negligible Battery Drain Current in Shutdown Undervoltage Lockout Self Protection for Overcurrent/Overtemperature The LTC®1734L is a low cost, single cell, constant-current/ constant-voltage Li-Ion battery charger controller. When combined with a few external components, the SOT-23 package forms a very small, low cost charger for single cell lithium-ion batteries. The LTC1734L is a lower charge current version of the LTC1734. The LTC1734L provides a fixed float voltage of 4.2V with 1% accuracy (for 4.1V and 4.15V float voltages, contact LTC Marketing). Constant current is programmed using a single external resistor between the PROG pin and ground. Manual shutdown is accomplished by floating the program resistor while removing input power automatically puts the LTC1734L into a sleep mode. Both the shutdown and sleep modes drain near zero current from the battery. Charge current can be monitored via the voltage on the PROG pin allowing a microcontroller or ADC to read the current and determine when to terminate the charge cycle. The output driver is both current limited and thermally protected to prev...