The AP1603 from Diodes Incorporated is a DC to DC Converter with Input Voltage 0.9 to 5.5 V, Output Voltage 1 2 to 5.5 V, Output Current 1 0.2 mA, Operating Temperature -40 to 85 Degree C, Storage Temperature -65 to 150 Degree C. Tags: Surface Mount, Boost/Step Up. More details for AP1603 can be seen below.