This part is a kind of semiconductor called 1SMB5920.

Function of this product has PLASTIC SURFACE MOUNT ZENER DIODES 3 WATTS 3.3.200 VOLTS.

Manufacturers : Motorola Inc

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Some of the text within the PDF file :

MOTOROLA SEMICONDUCTOR TECHNICAL DATA 3 Watt Plastic Surface Mount Silicon Zener Diodes This complete new line of 3 Watt Zener Diodes offers the following advantages. Specification Features: • A Complete Voltage Range 3.3 to 200 Volts • Flat Handling Surface for Accurate Placement • Package Design for Top Side or Bottom Circuit Board Mounting • Available in Tape and Reel Mechanical Characteristics: CASE: Void-free, transfer-molded plastic MAXIMUM CASE TEMPERATURE FOR SOLDERING PURPOSES: 260°C for 10 seconds FINISH: All external surfaces are corrosion resistant with readily solderable leads POLARITY: Cathode indicated by molded polarity notch. When operated in zener mode, cathode will be positive with respect to anode. MOUNTING POSITION: Any WEIGHT: Modified L-Bend providing [ ... ]

1SMB5920 PDF Datasheet Download