8A, 4MHz, Monolithic Synchronous Step-Down Regulator

The LTC3418 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 from 0.8V to 5V while delivering up to 8A of output current. The internal synchronous power switch increases efficiency and eliminates the need for an external Schottky diode. Switching frequency is set by an external resistor or can be synchronized to an external clock. OPTI-LOOP® compensation allows the transient response to be optimized over a wide range of loads and output capacitors.

The LTC3418 can be configured for either Burst Mode operation or forced continuous operation. Forced continuous operation reduces noise and RF interference while Burst Mode operation provides high efficiency by reducing gate charge losses at light loads. In Burst Mode operation, external control of the burst clamp level allows the output voltage ripple to be adjusted according to the requirements of the application. A tracking input in the LTC3418 allows for proper sequencing with respect to another power supply.

Applications

* Microprocessor, DSP and Memory Supplies

* Distributed 2.5V, 3.3V and 5V Power Systems

* Automotive Applications

* Point of Load Regulation

* Notebook Computers

* High Efficiency: Up to 95%

* 8A Output Current

* 2.25V to 5.5V Input Voltage Range

* Low RDS(ON) Internal Switch: 35mΩ

* Tracking Input to Provide Easy Supply Sequencing

* Programmable Frequency: 300kHz to 4MHz

* 0.8V ±1% Reference Allows Low Output Voltage

* Quiescent Current: 380μA

* Selectable Forced Continuous/Burst Mode® Operation with Adjustable Burst Clamp

* Synchronizable Switching Frequency

* Low Dropout Operation: 100% Duty Cycle

* Power Good Output Voltage Monitor

* Overtemperature Protected

* 38-Lead Low Profile (0.75mm) Thermally Enhanced QFN (5mm × 7mm) Package