The Si4590DY from Vishay is a MOSFET with Continous Drain Current 3.4 A, Drain Source Resistance 47 to 205 milliohm, Drain Source Breakdown Voltage -100 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage -1.2 to 2.5 V. Tags: Surface Mount. More details for Si4590DY can be seen below.