The Si5902BDC from Vishay is a MOSFET with Continous Drain Current 4 A, Drain Source Resistance 53 to 100 Milliohm, Drain Source Breakdown Voltage 30 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage 1.5 to 3 V. Tags: Surface Mount. More details for Si5902BDC can be seen below.