DN05126/D, High-Efficiency QR Flyback Adapter with USB-PD/Type-C Output Utilizing NCP1342

DN05126/D, Reference design for the NCP1342 is a highly-integrated quasi-resonant flyback controller suitable for designing high-performance off-line power converters. With an integrated active X2 capacitor discharge feature, the NCP1342 enables no-load power consumption below 70 mW. The quasi-resonant operating mode features a proprietary valley-lockout circuitry ensuring stable valley switching down the 6th valley. After the 6th valley the controller transitions to a frequency foldback mode to reduce switching losses in lighter load conditions. Secondary side synchronous rectification (SR) is implemented with the NCP43080 for optimized efficiency across all operating modes. The NCP43080 features precise zero current turn off and 12 ns turn-off delay from current sense to the driver allowing for the optimal SR conduction period in quasi-resonant mode