This document is a technical manual on Fairchild Power Switch (FPS). FPS is an AC-DC conversion design assistant that helps users design and optimize SMPS. FPS can automatically generate high-quality SMPS designs based on input voltage and current, load voltage and current, switching frequency, power factor, efficiency, and other parameters.
This application note details the design procedure for offline flyback AC-DC converters utilizing Fairchild's FPS (Flyback Power Supply) controller family. It explains the principle of operation where the MOSFET and PWM controller are integrated into a single chip, simplifying the SMPS design compared to discrete solutions. The guide aims to help designers complete SMPS designs quickly using the provided software tools and procedures. This manual is written in Chinese.
For universal input applications, D should typically be set between 15% and 20%.
For most ferrite core materials, B should typically be set between 0.3 T and 0.35 T.
When the wire diameter exceeds 1 mm, a current density of 5 A/mm² is typically used.