This part is a kind of semiconductor called 1N6620.

Function of this product has ULTRA FAST RECTIFIERS.

Manufacturers : Digitron Semiconductors

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Some of the text within the PDF file :

1N6620-1N6625 High-reliability discrete products and engineering services since 1977 ULTRA FAST RECTIFIERS FEATURES  Available as “HR” (high reliability) screened per MIL-PRF-19500, JANTX level. Add “HR” suffix to base part number.  Available as non-RoHS (Sn/Pb plating), standard, and as RoHS by adding “-PBF” suffix. MAXIMUM RATINGS Part number Reverse voltage Operating current (1) Volts Amps 1N6620 200 2.0 1N6621 400 2.0 1N6622 600 2.0 1N6623 800 1.5 1N6624 900 1.5 1N6625 1000 1.5 Operating Temperature: -65°C to +175°C Storage Temperature: -65°C to +200°C Note 1: TL = +55°C, L=.375 inch for axial parts. Derate linearly at 0.80%/°C for TL >+55°C. Note 2: Test pulse = 8.3ms, half sine wave. Note 3: Independent of heatsinking. Operating curren [ ... ]

1N6620 PDF Datasheet Download