General Description
This special device is a synchronous buck-boost DC/DC converter which can handle input voltages above, below, or equal to the output voltage.
Due to the internal structure of the AS1331 which is working continuously through all operation modes this device is ideal for dual or triple cell alkaline/NiCad/NiMH as well as single cell Li-Ion battery applications.

Key Features
■ Input Voltage Range: 1.8V to 5.5V
■ Output Voltages:
    - Fixed: 2.5V, 3.0V, 3.3V
    - Adjustable: 2.5V to 3.3V
■ Output Current: 300mA @ 3.3V
■ Up to 90% efficiency
■ Power Good
■ Output Disconnection in Shutdown
■ Automatic transition between Buck and Boost mode
■ Ultra Low Quiescent Current: 22µA, Shutdown Current <1µA (Active Low)
■ Short-Circuit Protection
■ Low Battery detection
■ Over Temperature Protection
■ 10-pin 3x3mm TDFN package

Applications
    The AS1331 is an ideal solution for handheld computers, handheld instruments, portable music players and PDA’s. Two and three cell Alkaline, NiCd or NiMH or single cell Li battery powered products.