NCP1937BADAPGEVB: 90 W Adapter PFC+QR 10 MW Evaluation Board

The combo IC integrates power factor correction (PFC) and quasi-resonant flyback functions that are essential for implementing compact and efficient switch-mode power supplies for adapter applications. The PFC stage has a power factor close to unity with maximum frequency clamping when operating in critical conduction mode (CrM). The circuit integrates all the functions required to build a robust and compact PFC stage while minimizing the number of external components. The quasi-resonant current mode flyback stage has a proprietary valley lock circuit to ensure stable valley switching. The system operates until the 4th valley and switches to frequency foldback mode with minimum frequency clamping after the 4th valley to eliminate audible noise. Skip mode operation achieves excellent efficiency at light load conditions while consuming very low standby power.


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 incorporates all the features necessary for building a robust and compact PFC stage while minimizing the number of external components. stable valley switching. This system works down to the 4th valley and toggles to a frequency foldback mode with a minimum frequency clamp beyond the 4th valley to eliminate audible noise. Skip mode operation allows excellent efficiency in light load conditions while consuming very low standby power consumption.