摘要
从数字电路PCB馈电网络等效电路和CMOS门电路模型出发,提出数字电路瞬态切换时负载阻抗变化导致板上电源系统的△I噪声,并依照阻抗匹配和信号完整性要求,提出采用阻尼的LC去耦网络,在不降低输出信号完整性要求的情况下,一方面可以降低电源系统的△I噪声,另一方面还将噪声电流从PCB板上的配电网络转移到IC电路的局部,降低辐射噪声。计算和仿真结果证明了分析的正确性,可作为设计依据。实验结果验证了LC去耦网络能显著减轻辐射干扰(RFI)。
Based on the equivalent circuits of the power network of digital printed circuit board （ PCB ） and the model of CMOS gates, it is presented in this paper that the impedance variation during the transient switching of digital gates is the cause △I noise in the power supply system. Thus, from the view of impedance matching and signal integrity, the decoupling method using the damped LC decoupling network is presented. It is verified by the simulation results that the damped LC decoupling network can both reduce the △I noise and transfer the noise from the power network to the local area of the digital IC without destroying the integrity of output signal. Based on the simulation results, some design rules are derived. The effect of the damped LC decoupling network on reducing the RFI noises is verified by the experiment results.
出处
《电工技术学报》
EI
CSCD
北大核心
2007年第4期14-20,共7页
Transactions of China Electrotechnical Society
基金
国家自然科学基金资助项目(50077020)。
