BC108 family

The BC107, BC108 and BC109 are general-purpose low power silicon NPN bipolar junction transistors found very often in equipment and electronics books/articles from Europe, Australia[1] and many other countries from the 1960s.

They were created by Philips and Mullard in 1963 and introduced in April 1966.

Initially in metal (TO-18) packages, the range expanded over time to include other package types, higher voltage ratings, and a better selection of gain (hFE and hfe) groupings, as well as complementary PNP types.

Some manufacturers have specified their parts with a higher power dissipation rating (Ptot) than others.

The BC548 is an example of the modern low-cost member of this family, still in a through-hole package, while the BC848 is the surface-mount version.