The LD39100 from STMicroelectronics is a LDO Voltage Regulator with Input Voltage 3 to 5.5 V, Output Voltage 1.2 to 3.3 V, Dropout Voltage 200 mV, Output Current 1 A, Quiescent Current 0.02 mA. Tags: Surface Mount. More details for LD39100 can be seen below.