APT电源芯片过流保护设计和检测方法优化

Design and Detection Methods of APT Power Overcurrent Protection

平均功率追踪(Average Power Tracking, APT)电源芯片过流失效甚至烧毁会导致整个无线移动通信终端设备无法正常工作。针对这一问题,结合降压(Buck)模式APT电源芯片失效的场景,提出了通过优化过流保护电路参数和有效拦截因制造工艺波动而导致不良电源芯片漏测的措施。一方面,在设计过流保护电路时,选取不同电感值的储能电感,对比不同电感值电路的电流纹波大小,分析不同纹波大小和芯片过流保护之间的关系,给出了通过选择合适的电感值来提高电源过流保护的方法。另一方面,在APT电源芯片生产测试环节使用By Pass模式,直接评估芯片的最大负载电流值与过流保护电流值,有效拦截过流保护不良的芯片。通过以上措施,无线移动通信终端设备的APT电源芯片过流保护的性能得到了质的飞跃,市场产品因为APT电源过流烧毁的概率几乎为0,产品质量信誉得到了很大的提升。

Failure or even burning down generated from Average Power Tracking(APT)power overcurrent would cause the overall breakdown of terminal equipment in mobile wireless communication.Two effective methods aiming to solve the problem for commonly Buck mode APT power were proposed in this article.Those are to properly design overcurrent protection circuits and effectively intercept fluctuations in the manufacturing process.On the one hand,we used different inductors with different inductance values in overcurrent protection circuits,analyzed the relationship between different ripple sizes and chip overcurrent protection,and provided a method to improve power overcurrent protection by selecting appropriate inductance values.On the other hand,we effectively intercepted defective chips by setting the APT power supply in the By Pass mode through comparing the maximum load current with the overcurrent protection current.Adopting the two methods,the overcurrent protection performance has been greatly improved in mobile wireless communication,and the overcurrent burnout caused by APT power overcurrent almost never occur again,which have greatly improved the quality and reputation of the product.