DESCRIPTION
The LTC®3556 is a highly integrated power management and battery charger IC for Li-Ion/Polymer battery applications. It includes a high efficiency current limited switching PowerPath manager with automatic load prioritization, a battery charger, an ideal diode, and three synchronous switching regulators (two bucks and one buck-boost). Designed specifically for USB applications, the LTC3556’s switching power manager automatically limits input current to a maximum of either 100mA or 500mA for USB applications or 1A for adapter-powered applications.

FEATURES
POWER MANAGER
■ High Effi ciency Switching PowerPathTM Controller
   with Bat-TrackTM Adaptive Output Control
■ Programmable USB or Wall Current Limit
   (100mA/500mA/1A)
■ Full Featured Li-Ion/Polymer Battery Charger
■ Instant-On Operation with a Discharged Battery
■ 1.5A Maximum Charge Current
■ Internal 180mΩ Ideal Diode Plus External Ideal Diode
   Controller Powers Load in Battery Mode
■ Low No-Load IQ when Powered from BAT (<30μA)

DC/DCs
■ Dual High Efficiency Buck DC/DCs (400mA/400mA IOUT)
■ High Effi ciency Buck-Boost DC/DC (1A IOUT)
■ All Regulators Operate at 2.25MHz
■ Dynamic Voltage Scaling on Two Buck Outputs
■ I2C Control of Enables, Mode, Two VOUT Settings
■ ENALL Pin with Power-Up Sequence Control
■ Low No-Load Quiescent Current: 20μA Each

APPLICATIONS
■ HDD-Based MP3 Players, PDAs, GPS, PMPs
■ Other USB-Based Handheld Products