A Jump To The Research And Design, Of Cycle Mode Flyback Switching Power Supply

With the development of the society, application requirements of Power Management Integrated Circuit and demands of AC/DC power circuit are increasing. Domestic manufacturers promote their AC/DC production to gain larger market share from foreign companies. Compared with the foreign AC/DC production, domestic production has some defects. But with the increasing investment input, the technology gap has been narrowed.Flyback AC/DC production has high requirement of design and quality, high-performanced production had the features of high integration, low cost, high efficiency and low power consumption. At present, this circuit is applied to lithium battery charger, LED driver and adapter, which need utility power input and have power output of less than 100W.Pulse skip modulation is a popular style which applied to low power output and low cost circuits. This modulation style has the merits of high efficiency, stable frequency response, high response speed and low use ratio of switch.This paper introduces a flyback converte circuit which is modulated by pulse skip style and applied to AC/DC converter. The input is 85～265VAC and output is 5w, it can be applied to lithium battery charger and LED driver. Modular analysis, contrastive analysis and design work of this circuit is introduced in this paper. Through the tapeout test, function and performance of this circuit have reached the demand designed and met the requirements of SPEC.