摘要
反激式开关电源因其结构简单、抗干扰能力强且成本较低,在家用电器、小功率设备及便携式适配器等领域的应用日益广泛,其相关的失效问题也随之增多,对电源电路的可靠性设计提出了更高要求。首先,阐述了反激式开关电源初级侧吸收回路的工作原理。随后,结合一起典型失效案例,通过收集失效背景信息、分析开关电源板上器件的失效机理、开展电路原理分析、测试关键节点波形及结合相关理论计算与推导,确认该开关电源板失效的根本原因在于初级侧吸收回路设计不当,导致开关金属氧化物半导体(MOS)管承受的漏感尖峰电压超出其耐压能力而击穿。最后,通过改进吸收回路(增加钳位二极管)并经过整机功能验证,确认该优化方案有效解决了失效问题。
Flyback switching power supplies are increasingly widely used in household appliances,low-power devices and portable adapters due to their simple structure,strong anti-interference ability and low cost.As a result,the related failure problems have also increased,which puts forward higher requirements for the reliability design of power supply circuits.Firstly,the working principle of the absorption circuit on the primary side of the flyback switching power supply is expounded.Subsequently,by combining a typical failure case,through collecting the failure background information,analyzing the failure mechanism of the devices on the switching power supply board,conducting circuit principle analysis,testing the waveforms of key nodes,and combining relevant theoretical calculations and derivations,it was confirmed that the fundamental cause of the failure of this switching power supply board lies in the improper design of the primary side absorption circuit.This causes the leakage inductance peak voltage endured by the switching metal-oxide-semiconductor(MOS)transistor to exceed its withstand voltage capacity and lead to breakdown.Finally,by improving the absorption circuit(adding a clamping diode)and verifying the overall machine function,it was confirmed that the optimization scheme effectively solved the failure problem.
作者
陈铁柱
林俊威
刘康卓
何胜宗
CHEN Tiezhu;LIN Junwei;LIU Kangzhuo;HE Shengzong(CEPREI,Guangzhou 511370,China)
出处
《电子质量》
2025年第12期68-74,共7页
Electronics Quality
关键词
反激式开关电源
失效分析
吸收回路
漏感尖峰
flyback switching power supply
failure analysis
snubber circuit
leakage inductance spike
