The Si9933CDY from Vishay is a MOSFET with Continous Drain Current -4 A, Drain Source Resistance 48 to 94 Milliohm, Drain Source Breakdown Voltage -20 V, Gate Source Voltage -12 to 12 V, Gate Source Threshold Voltage -1.4 to -0.6 V. Tags: Surface Mount. More details for Si9933CDY can be seen below.