The LTC3642 is a high efficiency step-down DC/DC converter with internal high side and synchronous power switches that draws only 12A typical DC supply current at no load while maintaining output voltage regulation. The LTC3642 can supply up to 50mA load current and features a programmable peak current limit that provides a simple method for optimizing efficiency in lower current applications. The LTC3642's combination of Burst Mode operation, integrated power switches, low quiescent current, and programmable peak current limit provides high efficiency over a broad range of load currents. With its wide 4.5V to 45V input range and internal overvoltage monitor capable of protecting the part through 60V surges, the LTC3642 is a robust converter suited for regulating a wide variety of power sources. Additionally, the LTC3642 includes a precise run threshold and soft-start feature to guarantee that the power system start-up is well-controlled in any environment. The LTC3642 is available in the thermally enhanced 3mm x 3mm DFN and MS8E packages.