高速多负载总线的板级信号完整性仿真与分析

Simulation and Analysis on Board-level Signal Integrity of High Speed Multi-load Bus

介绍高速数字电路中板级信号完整性的重要性,结合实际工程问题,采用SPECCTRAQuset软件,对多负载总线板级信号完整性进行仿真。由于多板互连、载荷不均等引起的反射、震铃、串扰等,破坏了信号的完整性,导致信号边沿不能严格单调,引起接收端对信号的误判。通过负载端接匹配电阻的方法提高信号完整性,并对改进后的拓扑结构进行Reflection仿真。仿真结果表明,改进后的信号边沿严格单调,质量有明显改善,可以指导原理图的修改,避免重复制板,节约时间和设计成本,具有实际工程应用参考价值。

The importance of board-level signal integrity in high-speed digital circuits is introduced.Combined with the actual engineering problems,SPECCTRAQuset software is used to simulate the signal integrity of multi-load bus board.As the integrity of the signal is destroyed by reflection,bells,crosstalk caused by multi-board interconnection and uneven load,the edge of the signal cannot be strictly monotonous,thus making the receiver misjudges the signal.The signal integrity could be improved by the matching resistance of the load end.And Reflection simulation on the modified topology indicates that the improved signal edge is strictly monotonous and the quality obviously improved,and this can guide the revision of the schematic diagram,avoid duplicating board,save time and design cost,and thus is of the reference value for practical engineering application.