The Si5504BDC from Vishay is a MOSFET with Continous Drain Current 3.7 A, Drain Source Resistance 53 to 235 Milliohm, Drain Source Breakdown Voltage -30 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage -3 to 3 V. Tags: Surface Mount. More details for Si5504BDC can be seen below.