Design And Implementation Of A New Flyback Switching Power Supply

Flyback switching power supply is widely used in charger,printer,built-in power supply,fax machine,LED lighting,router,adapter and other low-power AC/DC converters within 150 W due to its low cost,simple structure,easy to isolate and other advantages.At present,the widely used flyback switching power supply has the defects of low reliability and low average efficiency.This paper studies a new type of flyback switching power supply.In this paper,three modulation techniques and two feedback techniques of flyback switching power supply are studied in detail,and their advantages and disadvantages are analyzed and compared.In combination with the needs of companies such as HUAWEI,ETHETA,MASS POWER,and designed a new type of the flyback switching power supply,the power supply design specifications compared with widely used on the market at present had the comprehensive promotion of switch power supply.The hybrid modulation technology and primary edge feedback(PSR)technology are used in the power supply.The hybrid modulation technology can make the power supply work efficiently under various load conditions,and then improve the average efficiency of the power supply.PSR structure can reduce the complexity of peripheral circuits.On the basis of the design,this switching power supply is developed,and the performance of the developed switching power supply is tested.The results show that the technical indexes of the flyback switching power supply are better than the design indexes.Good products must have high reliability,safety test and failure analysis of products is an important means of product reliability.In this paper,a set of safety test scheme is designed for the developed switching power supply.Power management chip is the core component of switching power supply.The current failure analysis of power management chip is that the positioning of the chip as a whole is not accurate,and no scientific failure analysis method is adopted,which leads to long customer complaint processing time and low success rate.To solve the above problems,this paper subdivides the chip into died level and package level.The fishbone diagram method was used for root cause analysis and a specific failure analysis process was developed.The failure analysis process was used to analyze 50 unqualified products.The results show that compared with the original failure analysis process,the failure analysis process developed in this paper increases the success rate by 18%.