ZVS and ZCS High Efficiency Low Profile Adapter
The paper presents an innovative design that delivers 65W of power at more than 91% efficiency in a footprint of a business card using a high frequency quasi-resonant fly-back topology with synchronous rectification, while maintaining a reasonable low cost of the AC/DC adapter. Topology and techniques for obtaining ZVS and ZCS for high frequency and high voltage switching are described. The goal of the design is maintaining a reasonable temperature rise of the case while delivering 65W power in a reduced volume. The resulting product increases more than twice the power density compared to the standard notebook adapters.