IC Combines 500-mA Battery Charger With 250-mA Step-Down Converter

The AAT2556 is AnalogicTech’s first multi-function SystemPower IC to combine a battery charger and buck converter in a single package. This new device offers a highly compact and power efficient solution for a growing number of single-cell lithium-ion/polymer battery-based ultra-portable systems, such as Bluetooth headsets, handheld GPS devices, and high-end portable music players.

AAT2556’s buck converter delivers up to 250 mA. It operates in both fixed and variable frequency modes to support high efficiency levels that range up to 96%. No load quiescent current is 30 µA. Its 1.5-MHz switching frequency minimizes the size of external components and keeps switching losses low.

The battery charger is a complete constant current/constant voltage linear charger. Intended to operate from USB or AC adapter inputs across a 4.0- to 6.5-V input range, it integrates a charging device and reverse blocking diode to regulate battery charge voltage and current for single-cell lithium-ion/polymer batteries. Charging current is programmable from 15 mA to 500 mA via an external resistor. The AAT2556 adds over-voltage, over-current, and thermal protection circuits.

Advanced Analogic Technologies Inc.
www.analogictech.com