I thought the same thing, how could there be no PFC? The UC3842B is not that old. [1] But I guess time has flown... The PFC requirement was part of Energy Sta

I thought the same thing, how could there be no PFC? The UC3842B is not that old. [1] But I guess time has flown... The PFC requirement was part of Energy Star 5.0 which was 2009. [2] [1] https://www.ti.com/lit/ds/symlink/uc2845.pdf https://www.ti.com/lit/ds/symlink/uc2845.pdf Great generic current mode control circuit good for lots of things, not just supplies. Still in active use today. Datasheet is like a textbook. [2] https://en.wikipedia.org/wiki/Power_factor#cite_note-30 https://en.wikipedia.org/wiki/Power_factor#cite_note-30