A reference designator is used to identify a component within an electrical schematic or on a printed circuit board (PCB). It consists of one or two letters followed by numbers (e.g., C15, D10, J5, R18). Each location on a PCB will have unique reference designators and there are distinct symbols for different types of electronic components.
A reference designator indicates where a particular printed circuit board assembly (PCBA) fits on the board within the BOM.
A PCB has two unique part numbers. The first part number Is stamped on the board and is used to identify the blank board without any components. The second part number is typically printed on a label and identifies the finished board with all the different components.
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