Analysis and Design for Output Voltage Regulation in Constant-on-Time-Controlled Fly-Buck Converter

Fly-buck converter is a multi-output with the structure of synchronous buck on primary side and flyback secondary side, can be utilized in various applications due to its many advantages. In terms control, fly-buck has same as converter, allowing constant-on-time (COT) control applied converter. However, inherent energy transfer principle, primary-side output voltage regulation COT controlled converters may poor, which deteriorate overall performance. Therefore, capacitor must carefully designed improve characteristics. this paper, theoretical analysis conducted, based this, design guideline for considering presented. The validity guidelines was verified using 5 W prototype telecommunication auxiliary power supply.