The TSR 1-0518SM from Traco Power is a DC to DC Converter with Input Voltage 3 to 5.5 V, Output Voltage 1 1.8 V, Output Current 1 1 A, Operating Temperature -40 to 85 Degree C, Storage Temperature -55 to 125 Degree C. Tags: Surface Mount, Buck/Step down. More details for TSR 1-0518SM can be seen below.