DESCRIPTION
The SP6651A is a 800mA synchronous buck regulator which is ideal for portable applications that use a Li-Ion or 3 cell alkaline/NiCD/NiMH input. The SP6651A’s proprietary control loop, 20µA light load quiescent current, and 0.3Ω power switches provide excellent efficiency across a wide range of output currents. As the input battery supply decreases towards the output voltage the SP6651A seamlessly transitions into 100% duty ratio operation further extending useful battery life. The SP6651A is protected against overload and short circuit conditions with a precise inductor peak current limit. Other features include programmable under voltage lockout and low battery detection, externally programmed output voltage down to 1.0V, logic level shutdown control, and 140°C over temperature shutdown.

FEATURES
■ DFN Package (3mm x 3mm)
■ Ultra-low 20µA Quiescent Current
■ 98% Efficiency Possible
■ 800mA Output Current
■ 2.7V to 5.5V Input Voltage Range
■ Output Adjustable Down to 1.0V
■ No External FET’s Required
■ 1.25A Inductor Peak Current Limit
■ 100% Duty Ratio Low Dropout Operation
■ 80µA Light Load Quiescent Current in Dropout
■ Over Temperature Protection
■ Logic Shutdown Control
■ Programmable UVLO and Adaptive Battery Low Output

APPLICATIONS
■ PDAs
■ DSCs
■ MP3 Players
■ USB Devices
■ Point of Use Power