The 1SMA5939BT3G from onsemi is a Power Diode with Forward Current 0.0096 A, Forward Voltage 37.05 to 40.95 V, Reverse Current 0.5 uA, Reverse Voltage 29.7 V, Repetitive Peak Reverse Voltage 29.7 V. Tags: Surface Mount. More details for 1SMA5939BT3G can be seen below.