Research On Switching Noise Suppression Methods

With the function continuously growing strong, rising complexity, decreasing power consumption of modern electronic products, fasting electronics operating clock frequency and lowing the power supply voltage, the corresponding circuit design allows noise margin and timing margin will become lower. Large Scale Integrated Circuit(LSIC) internal transistor’s opening simultaneously will produce transient currents. Simultaneous Switching Noise(SSN) caused by transient currents will seriously affect the power distribution network. The Power Distribution Network(PDN) is the core of the high-speed circuit design. In circuit, all devices are connected to the PDN. Whether PDN design scientific or not determines the success or failure of the product design. The SSN suppression acting as an important part of the PDN designs, it becomes particularly important in high-speed circuits.In the past, the SSN gained sufficient attention. And researchers have proposed a number of methods to suppress propagation of SSN, and those methods are effective in a limited frequency band. This paper focuses on effectively elimination of the impact of SSN in the PDN. Based on the study of the basic theory in the signal integrity, this paper analyzes the sources of noise PDN, and describes the formation mechanism of SSN. According to their formation mechanism, several types designed to suppress SSN in traditional PDN are proposed, such as ones to increase the discrete decoupling capacitors, use differential line transmission signal, split power planes, etc. Analyzing the advantages and disadvantages of these methods will solve above problems arising in recent years. Electromagnetic Band Gap(EBG) structure is proposed for SSN suppression. Compared with this method, conventional PDN design has been greatly improved. This paper focuses on the EBG structure suppress SSN in mushroom EBG structure and coplanar EBG structure, through theoretical derivation and software simulation of EBG structure SSN suppression mechanism.EBG structure has developed rapidly and many researchers have proposed a variety of EBG structure used to suppress SSN. As to these EBG structure, this paper analyzes the advantages and disadvantages of them, and summarizes the experiences of predecessors, who innovatively proposed a Horizontal Cascaded EBG structure. The structure belongs to the coplanar EBG structure, which is consists of two coplanar structure of the basic unit of a combination of different periods in accordance with certain rules. Because of its cascading features, the proposed EBG structure can obtain the advantages of these two EBG structures, and if the lower limit of the cutoff frequency EBG structure and ultra-wideband EBG structures cascaded, horizontal cascaded EBG structure will be better. This paper describes the implementation process of the plane cascaded EBG structure in details. The structure can achieve the ultra-wideband from 0.5GHz to 20 GHz at the restraining depth of-30 d B with the software simulation. This paper uses equivalent circuit modeling approaching to analyze the stop band characteristics and inheritance of the proposed EBG structure from parallel resonant LC resonator. At last, time-domain simulation results shows a significantly improvement on the signal integrity if differential signaling is adopted.