DESCRIPTION
The LTC®3405A-1.5/LTC3405A-1.8 are high efficiency monolithic synchronous buck regulators using a constant frequency, current mode architecture. Supply current during operation is only 20µA and drops to <1µA in shutdown. The 2.5V to 5.5V input voltage range makes the LTC3405A-1.5/LTC3405A-1.8 ideally suited for single Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems.

FEATURES
■ High Efficiency: Up to 93%
■ Very Low Quiescent Current: Only 20µA
   During Operation
■ 300mA Output Current at VIN = 3V
■ 2.5V to 5.5V Input Voltage Range
■ 1.5MHz Constant Frequency Operation
■ No Schottky Diode Required
■ Low Dropout Operation: 100% Duty Cycle
■ Stable with Ceramic Capacitors
■ Shutdown Mode Draws <1µA Supply Current
■ ±3% Output Voltage Accuracy
■ Current Mode Operation for Excellent Line and
   Load Transient Response
■ Overtemperature Protected
■ Low Profile (1mm) ThinSOTTM Package

APPLICATIONS
■ Cellular Telephones
■ Personal Information Appliances
■ Wireless and DSL Modems
■ Digital Still Cameras
■ MP3 Players
■ Portable Instruments