The ADP3808 is a complete Li-Ion battery charging controller for 3- or 4-cell battery packs. The device combines accurate final battery charge voltage control with constant current control to simplify the implementation of constant-current, constant-voltage (CCCV) chargers. The final battery charge voltage is programmable between 4.0 V to 4.5 V per cell, allowing the charging of various cell types. The charge current is programmable over a wide range from trickle charging to full charging. The system current sense amplifier includes an ac adapter detection output to signal that the adapter is connected. The bootstrapped synchronous driver controls two N-channel MOSFET transistors for high efficiency charging at a low system cost.