摘要：
As semiconductor technologies have been shrinking, the speed of circuits, integration density, and the number of I/O interfaces have been significantly increasing. As a consequence, electromagnetic emanation (EME) becomes a critical issue in digital system designs. Electronic devices must meet electromagnetic compatibility (EMC) requirements to ensure that they operate properly, and safely without interference. I/O buffers consume high currents when they operate. The bonding wires, and lead frames are long enough to play as efficient antennas to radiate electromagnetic interference (EMI). Therefore, I/O switching activities significantly contribute to the EMI. In this paper, we evaluate and analyze the impact of I/O switching activities on the EME. We will change the circuit configurations such as the supply voltage for I/O banks, their switching frequency, driving current, and slew rate. Additionally, a trade-off between the switching frequencies and the number of simultaneous switching outputs (SSOs) is also considered in terms of EME. Moreover, we evaluate the electromagnetic emissions that are associated with the different I/O switching patterns. The results show that the electromagnetic emissions associated I/O switching activities depend strongly on their operating parameters and configurations. All the circuit implementations and measurements are carried out on a Xilinx Spartan-3 FPGA.%随着半导体技术的不断萎缩,电路的速度、集成密度和I/O接口的数量显著增加,因此,电磁辐射(EME)成为数字系统设计中的一个关键问题.电子设备必须满足电磁兼容性(EMC)的要求,以确保其正常运行,且不受干扰.I/O缓冲器在工作时消耗大电流.连接线和引线框足够长,可以作为有效的天线发射电磁干扰(EMI).因此,I/O交换活动对电磁干扰有显著影响.本文对I/O交换活动对电磁环境的影响进行了评价和分析.改变电路配置,如I/O组的供电电压、他们的开关频率、驱动电流和转换率.此外,还考虑了交换频率与同时交换输出(SSOs)数量之间的权衡问题.此外,还评估了与不同I/O开关模式相关的电磁辐射.结果表明,与I/O开关活动相关的电磁辐射强烈依赖于他们的工作参数和配置.所有电路实现和测量都是在Xilinx Spartan-3 FPGA上进行的.
