The FDC638APZ from onsemi is a MOSFET with Continous Drain Current -4.5 A, Drain Source Resistance 37 to 72 milliohm, Drain Source Breakdown Voltage -20 V, Gate Source Voltage -12 to 12 V, Gate Source Threshold Voltage -1.5 V. Tags: Surface Mount. More details for FDC638APZ can be seen below.