High Efficiency Switch Mode Li-Ion Battery Charger



The ADP3808A 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. The ADP3808A is specified over the extended commercial temperature range of 0°C to 100°C and is available in a 24−lead LFCSP package.

Features

•Selectable 3−Cell or 4−Cell Operation

•Adjustable 4.0 V to 4.5 V Per Cell

•High End-of-Charge Voltage Accuracy

  ♦±0.4% @ 25°C

  ♦±0.6% @ 5°C to 55°C

  ♦±0.8% @ 0°C to 100°C

•Programmable Charge Current, Including Trickle Charge

•Bootstrapped Synchronous Drive for External N−Channel MOSFETs

•Programmable Oscillator Frequency

•This is a Pb−Free Device



Applications

•Portable Computers

•Portable Equipment