The LTM4638 from Analog Devices is a DC to DC Converter with Input Voltage 3.1 to 20 V, Output Voltage 1 0.6 V, Output Current 1 15000 mA, Operating Temperature -40 to 125 Degree C, Storage Temperature -55 to 125 Degree C. Tags: Surface Mount, Buck/Step down. More details for LTM4638 can be seen below.