ADP3806

a FEATURES Li-Ion Battery Charger Three Battery Voltage Options Selectable 12.525 V/16.700 V Selectable 12.600 V/16.800 V Adjustable High End-of-Charge Voltage Accuracy ؎0.4% @ 25؇ C ؎0.6% @ 5 ؇ C to 55Њ C ؎0.7% @ 0 ؇ C to 85؇ C Programmable Charge Current with Rail-to-Rail Sensing System Current Sense with Reverse Input Protection Softstart Charge Current Undervoltage Lockout Bootstrapped Synchronous Drive for External NMOS Programmable Oscillator Frequency Oscillator SYNC Pin Low Current Flag Trickle Charge APPLICATIONS Portable Computers Fast Chargers High-Frequency Switch Mode Li-Ion Battery Charger ADP3806 GENERAL DESCRIPTION The ADP3806 is a complete Li-Ion battery-charging IC. The device combines high output voltage accuracy with constant current control to simplify the implementation of ConstantCurrent, Constant-Voltage (CCCV) chargers. The ADP3806 is available in three options. The ADP3806-12.6 guarantees the final battery voltage be selected to 12.6 V or 16.8 V ± 0.6%, the ADP3806-12.5 guarantees 12.525 V/16.7 V ± 0.6% and the ADP3806 is adjustable using two external resistors to set the battery voltage. The current sense amplifier has rail-to-rail inputs to accurately operate under low drop out and short circuit conditions. The charge current is programmable with a dc voltage on ISET. A second differential amplifier senses the system current across an external sense resistor and outputs a linear voltage on the ISYS pin. The bootstrapped synchronous driver allows ...