NCP1937 Datasheet (ON Semiconductor) - Combination Power Factor Correction and Quasi- Resonant Flyback Controllers

NCP1937, Combination Power Factor Correction and Quasi- Resonant Flyback Controllers

DATA SHEET www.onsemi.com Combination Power Factor Correction and QuasiResonant Flyback Controllers for Adapters NCP1937 This combination IC integrates power factor correction (PFC) and quasi resonant flyback functionality necessary to implement a compact and highly efficient Switched Mode Power Supply for an adapter application.

The PFC stage exhibits near unity power factor while operating in a Critical Conduction Mode (CrM) with a maximum frequency clamp.

The circuit incorpor

NCP1937 Features

* necessary for building a robust and compact PFC stage while minimizing the number of external components. The quasi

* resonant current

* mode flyback stage features a proprietary valley

* lockout circuitry, ensuring stable valley switching. This system works down to the 4th valley