1.2A, High Efficiency Step-Down DC/DC Converter

The LTC1265 is a monolithic step-down current mode DC/DC converter featuring Burst Mode™ operation at low output current. The LTC1265 incorporates a 0.3Ω switch (VIN =10V) allowing up to 1.2A of output current.

Under no load condition, the converter draws only 160µA. In shutdown it typically draws a mere 5µA making this converter ideal for current sensitive applications. In dropout the internal P-channel MOSFET switch is turned on continuously maximizing the life of the battery source. The LTC1265 incorporates automatic power saving Burst Mode operation to reduce gate charge losses when the load currents drop below the level required for continuous operation.

The inductor current is user-programmable via an external current sense resistor. Operation up to 700kHz permits the use of small surface mount inductors and capacitors.

Applications

* 5V to 3.3V Conversion

* Distributed Power Systems

* Step-Down Converters

* Inverting Converters

* Memory Backup Supply

* Portable Instruments

* Battery-Powered Equipment

* Cellular Telephones

* High Efficiency: Up to 95%

* Current Mode Operation for Excellent Line and Load Transient Response

* Internal 0.3Ω Power Switch (VIN = 10V)

* Short-Circuit Protection

* Low Dropout Operation: 100% Duty Cycle

* Low-Battery Detector

* Low 160µA Standby Current at Light Loads

* Active-High Micropower Shutdown: IQ < 15µA

* Peak Inductor Current Independent of Inductor Value

* Available in 14-pin SO Package