The 1N6638 from Semtech is a Space Qualified Diode with Forward Current 0.2 A, Forward Voltage 0.8 to 1.1 V, Reverse Current 35 to 500 uA, Reverse Voltage 150 V, Repetitive Peak Reverse Voltage 150 V. Tags: Through Hole. More details for 1N6638 can be seen below.