The 2SA1813 is covered by this 83.4 KB PDF datasheet, a PNP bipolar transistor according to the 2SA prefix of the Japanese JIS scheme. Expect tables of maximum ratings, typical characteristic curves and a package diagram showing lead assignment. A technician reaches for it when measuring a suspected shorted junction, confirming which pin is the collector, or comparing ratings with a candidate substitute. Always cross-check the part marking on the PCB, as small SMD codes may not show the full number.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @cyberlanelectonik. Enginerys does not host this file.
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