The Si4946CDY from Vishay is a MOSFET with Continous Drain Current 6.1 A, Drain Source Resistance 33 to 51.6 milliohm, Drain Source Breakdown Voltage 60 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage 1 to 3 V. Tags: Surface Mount. More details for Si4946CDY can be seen below.