The E0503S-1WR3 from MORNSUN is a DC to DC Converter with Input Voltage 4.5 to 5.5 V, Output Voltage 1 3.3 V, Output Current 1 15 to 152 mA, Output Power 1000 mW, Output Voltage 2 -3.3 V. Tags: Through Hole, Buck/Step down. More details for E0503S-1WR3 can be seen below.