1.25A, 4MHz, Synchronous Step-Down DC/DC Converter

The LTC3411 is a constant frequency, synchronous, step- down DC/DC converter. Intended for medium power applications, it operates from a 2.63V to 5.5V input voltage range and has a user configurable operating frequency up to 4MHz, allowing the use of tiny, low cost capacitors and inductors 2mm or less in height. The output voltage is adjustable from 0.8V to 5V. Internal sychronous 0.11Ω power switches with 1.6A peak current ratings provide high efficiency. The LTC3411’s current mode architecture and external compensation allow the transient response to be optimized over a wide range of loads and output capacitors.

The LTC3411 can be configured for automatic power saving Burst Mode operation to reduce gate charge losses when the load current drops below the level required for continuous operation. For reduced noise and RF interference, the SYNC/MODE pin can be configured to skip pulses or provide forced continuous operation.

To further maximize battery life, the P-channel MOSFET is turned on continuously in dropout (100% duty cycle) with a low quiescent current of 60μA. In shutdown, the device draws <1μA.

Applications

* Notebook Computers

* Digital Cameras

* Cellular Phones

* Handheld Instruments

* Board Mounted Power Supplies

* Small 10-Lead MSOP or DFN Package

* Uses Tiny Capacitors and Inductor

* High Frequency Operation: Up to 4MHz

* High Switch Current: 1.6A

* Low RDS(ON) Internal Switches: 0.110Ω

* High Efficiency: Up to 95%

* Stable with Ceramic Capacitors

* Current Mode Operation for Excellent Line and Load Transient Response