The BU90002GWZ from ROHM Semiconductor is a DC to DC Converter with Input Voltage 4 to 5.5 V, Output Voltage 1 3.3 V, Output Current 1 1000 mA, Operating Temperature -40 to 85 Degree C, Storage Temperature -55 to 150 Degree C. Tags: Surface Mount, Buck/Step down. More details for BU90002GWZ can be seen below.