A synchronous rectified flyback AC-DC converter using capacitor-coupled isolated communication

Abstract

This paper presents a synchronous rectified (SR) flyback AC-DC converter based on capacitor-coupled isolated communication. Instead of bulky opto-couples as isolators, the proposed converter integrates an isolated capacitor to accomplish communication between the primary and secondary side, in an attempt to reduce system size. In secondary side, an adaptive zero-current detector (ZCD) for driving synchronous rectifier is adopted to increase efficiency. The converter is designed and fabricated in a 0.18-m BCD process. The experimental results demonstrate that our scheme shrinks the isolator size by a factor of 52.24 times and simultaneously improves the system efficiency by 3% with ZCD.

A high-efficiency active clamped flyback AC-DC converter using an integrated digital isolator in isolated communication

“…However, the optocoupler cannot be integrated on chip and may introduce extra lowfrequency parasitic poles which will limit both the size and bandwidth of the converter [5,6,7]. Even worse, as temperature and working time increase, optocouplers will suffer from current transfer ratio (CTR) degradation [8]. Lots of methods have been put up to eliminate optocoupler in an isolated flyback converter.…”

A single input dual output converter with low cross regulation

“…For low to medium AC/DC power supply design, the Flyback converter [1,2,3,4] is a typical choice due to its simple structure, and easy to achieve multiple-output. Modern electronic products usually require several different voltages supply.…”