The AP61100Q from Diodes Incorporated is a DC to DC Converter with Input Voltage 2.3 to 5.5 V, Output Voltage 1 0.6 to 3.6 V, Output Current 1 1000 mA, Operating Temperature -40 to 125 Degree C, Storage Temperature -65 to 150 Degree C. Tags: Surface Mount, Buck/Step down. More details for AP61100Q can be seen below.