DESCRIPTION
The LTC®3558 is a USB battery charger with dual high effi ciency switching regulators. The device is ideally suited to power single-cell Li-Ion/Polymer based handheld applications needing multiple supply rails.

FEATURES
Battery Charger
■ Standalone USB Charger
■ Up to 950mA Charge Current Programmable via
   Single Resistor
■ HPWR Input Selects 20% or 100% of Programmed
   Charge Current
■ NTC Input for Temperature Qualified Charging
■ Internal Timer Termination
■ Bad Battery Detection

Switching Regulators (Buck and Buck-Boost)
■ Up to 400mA Output Current per Regulator
■ 2.25MHz Constant-Frequency Operation
■ Power Saving Burst Mode® Operation
■ Low Profi le, 20-Lead, 3mm × 3mm QFN Package

APPLICATIONS
■ SD/Flash-Based MP3 Players
■ Low Power Handheld Applications