Lifecycle score 30/100 (at_risk).
Status: obsolete
The BC547 transistor is confirmed obsolete by Digi-Key and no longer manufactured by major OEMs (NXP, ON Semi, Fairchild). No recent datasheets, errata, or PCNs exist (latest datasheets from 1999–2008), and multiple successor parts (BC548, BC549, 2N3904) are recommended. However, "DDF BC547" is not a valid manufacturer designation; confidence is medium due to this ambiguity, though the base BC547 status is clear.