The UN0309N3R2-T52 from UN Semiconductor is a MOSFET with Continous Drain Current 90 A, Drain Source Resistance 3.2 to 7.0 milli-ohm, Drain Source Breakdown Voltage 30 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage 1 to 2.5. Tags: Surface Mount. More details for UN0309N3R2-T52 can be seen below.