DESCRIPTION
The LTC®3700 is a constant frequency current mode stepdown (buck) DC/DC controller with excellent AC and DC load and line regulation. The on-chip 150mA low dropout (LDO) linear regulator can be powered from the buck controller’s input supply, its own independent input supply or the buck regulator’s output. The buck controller incorporates an undervoltage lockout feature that shuts down the controller when the input voltage falls below 2.1V.

FEATURES
■ Dual Output Regulator in Tiny 10-Pin MSOP
■ High Efficiency: Up to 94%
■ Wide VIN Range: 2.65V to 9.8V
■ Constant Frequency 550kHz Operation
■ 150mA LDO Regulator with Current Limit and
   Thermal Shutdown Protection
■ High Output Currents Easily Achieved
■ Burst Mode® Operation at Light Load
■ Low Dropout: 100% Duty Cycle
■ Current Mode Operation for Excellent Line and Load
   Transient Response
■ 0.8V Reference Allows Low Output Voltages
■ Low Quiescent Current: 260µA Total
■ Shutdown Mode Draws Only 10µA Supply Current
■ Common Power Good Output for Both Supplies

APPLICATIONS
■ Notebook Computers
■ Portable Instruments
■ One or Two Li-Ion Battery-Powered Applications