Research And Design Of A High Performance Fly-back Converter XD410

A high performance fly-back converter XD410is researched and designed in thispaper, and it is based on the project “Theoretical Research and Design of KeyTechnique for Power Management IC” belonged to the Institute of Electronic CADXidian University.Firstly, the paper introduces the technology and application background of fly-backconverter. Then a detail description of the operation mode and the control mode arepresented. The design and selection principle of the periphery devices is also taken intoconsideration in this paper. At last, some key sub-blocks and whole-chip simulation aredone to verify correction of the above theories. The designed chip XD410utilizes DCMoperation mode and peak current control mode. The system of XD410can realize theoutput modulation function with primary feedback or secondary feedback. The systemworks in a PWM mode with a control frequency of65kHz when the current load is atmedium or heavy, however, at a light load, the system frequency will gradually reduceto a mininum value of17kHz, the reduction relates to the current of load, and when itcomes to the case of no load, the power MOSFET will remain a completely off statues.The system also includes constant current and constant power compensation circuit torealize a constant current or constant voltage output function.The functions described above have been simulated on0.8um，5V/30V/600V BCDprocess by HspiceD. Experimental results show that the performance of XD410is good.