60V, 4A Synchronous Step-Down Regulator with Rail-to-Rail Programmable Output

The LTC3649 is a high efficiency 60V, 4A synchronous monolithic step-down regulator. The regulator features a single resistor programmable output voltage, internal compensation and high efficiencies over a wide VOUT range.

The step-down regulator operates from an input voltage range of 3.1V to 60V and provides an adjustable rail-to-rail output range from (VIN – 0.5V) to ground while delivering up to 4A of output current. The switching frequency is also adjusted with an external resistor. A user-selectable mode input is provided to allow the user to trade off ripple noise for efficiency at light loads; Burst Mode operation provides the highest efficiency at light loads, while forced continuous mode provides low output ripple. The MODE/SYNC pin can also be used to allow the user to synchronize the switching frequency to an external clock.

The LTC3649 operates with a peak current mode architecture that allows for fast transient response with inherent cycle-to-cycle current limit protection. It also features programmable output current limit, current monitoring and input voltage regulation.

Applications

* Industrial Applications

* Automotive Applications

* Wide VIN Range: 3.1V to 60V* Wide VOUT Range: 0V to (VIN – 0.5V)* Single Resistor VOUT Programming* Integrated 110mΩ Top N-Channel/50mΩ Bottom N-Channel MOSFETs* 95% Efficiency with 12VIN and 5VOUT* Regulated IQ: 440μA, Shutdown IQ: 18μA* Accurate Current Monitoring (±4%) without Sense Resistor* Accurate Resistor Programmable Frequency (300kHz to 3MHz) with ±50% Frequency Sync Range* Accurate Programmable Output Current* Input Voltage Regulation for MPPT Applications* ±0.8% Output Voltage Accuracy* Peak Current Mode Operation* Programmable Wire Drop Compensation* Burst Mode® Operation, Forced Continuous Mode* Internal Compensation and Programmable Soft-Start* Overtemperature Protection* Available in Thermally Enhanced 28-Lead (4mm × 5mm) QFN and TSSOP Packages