3A, 2MHz Monolithic Synchronous Regulator for DDR/QDR Memory Termination

The LTC3413 is a high efficiency monolithic synchronous step-down DC/DC converter utilizing a constant frequency, current mode architecture. It operates from an input voltage range of 2.25V to 5.5V and provides a regulated output voltage equal to (0.5)VREF while sourcing or sinking up to 3A of output current. An internal voltage divider reduces component count and eliminates the need for external resistors by dividing the reference voltage in half. The internal synchronous power switch with 85mΩ on-resistance increases efficiency and eliminates the need for an external Schottky diode. Switching frequencies up to 2MHz are set by an external resistor.

Forced-continuous operation in the LTC3413 reduces noise and RF interference. Fault protection is provided by an overcurrent comparator that limits output current during both sourcing and sinking operations. Adjustable compensation allows the transient response to be optimized over a wide range of loads and output capacitors.

Applications

* Bus Termination: DDR and QDR™ Memory, SSTL, HSTL, ...

* Notebook Computers

* Distributed Power Systems

* High Efficiency: Up to 90%

* ±3A Output Current

* Symmetrical Source and Sink Output Current Limit

* Low RDS(ON) Internal Switch: 85mΩ

* No Schottky Diode Required

* 2.25V to 5.5V Input Voltage Range

* VOUT = VREF/2

* ±1% Output Voltage Accuracy

* Programmable Switching Frequency: Up to 2MHz

* Power Good Output Voltage Monitor

* Overtemperature Protected

* Available in 16-Lead TSSOP Exposed Pad Package