The 1N3646 from Semtech is a Space Qualified Diode with Forward Current 0.6 to 0.26 A, Forward Voltage 5.00 V, Reverse Current 1.00 to 20.0 uA, Reverse Voltage 2500 V, Repetitive Peak Reverse Voltage 2500 V. Tags: Through Hole. More details for 1N3646 can be seen below.