The LT3955 from Analog Devices is a LED Driver IC with Input Voltage 4.5 to 60 V, Output Current 4200 mA, Number of Output 1, Switching Frequency 100 to 1000 KHz, Operating Temperature Range -40 to 125 Degree C. Tags: Surface Mount, DC-DC LED Driver. More details for LT3955 can be seen below.