The Si4459ADY from Vishay is a MOSFET with Continous Drain Current 29 A, Drain Source Resistance 3.9 to 7.75 milliohm, Drain Source Breakdown Voltage -30 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage -1 to -2.5 V. Tags: Surface Mount. More details for Si4459ADY can be seen below.