用新的总线转换模块升级IBA板

　　用新的总线转换模块升级IBA板

　　分布式电源架构（DPA）是流行在现代电信和数据通信设备，以及在数据中心的服务器。DPA拓扑传统上使用一个前端AC/DC转换器模块，该模块从交流电源产生高压直流输出。设计者通常更喜欢中间总线结构（IBA），因为要有效地将前端高直流电压（通常为48 V）转换为负载点所需的低电压，以在系统板上驱动电子负载。基于IBA的电力系统使用一个隔离的dc / dc转换模块，称为中间总线转换器（IBC）或简单总线转换器（图1），将前端高压输入总线转换为中间电平电压，例如9或12伏直流电压和更低电平。

　　Figure 1： Intermediate bus architecture （IBA） uses a bus converter to step-down high-voltage distribution bus to an intermediate level DC voltage.

　　The lower intermediate bus voltage makes it easy for system designers to use very efficient， high-density， nonisolated POLs （niPOLs） to further drive microprocessors， memory modules， and other electronic devices on the system boards. Over the years， the bus converter modules used in such IBA schemes have evolved tremendously. These converters now are available in a variety of industry-standard formats – such as open-frame， bricks， and surface-mountable modules – for upgrading the current IBA schemes implemented on system boards. While the majority of bus converter outputs are semi-regulated， some also offer fully regulated outputs.