A Study Of Signal Integrity And Power Integrity In High Speed Circuit

According to Moore’s law, electronic product development is in the direction of small,fast and cheap. IC manufacturing technology unceasing progress, falling on a chip size,the chip is gradually integrated into high speed circuit. The circuit at low speed cannot meet the needs of people’s daily life. In the era of high speed circuit, signal integrity and power integrity problems gradually aroused people’s attention. From the perspective of industry development, basic principle and simulation model, this thesis mainly research on the signal integrity and power integrity in high speed circuit. It can be divided into several aspects:1. Firstly, we research the transmission line model in high speed circuit. In high speed circuit the wire is no longer applicable. Based on the research of the transmission line equivalent model, we can deduce the relationship of current and voltage. Secondly,about the signal integrity theory research: mainly includes the signal reflection and crosstalk model, ringing, termination mode; Power integrity research: mainly includes the Power Deliver network, PDN system noise, decoupling capacitor and target impedance. Through the theory modeling study of signal integrity and power integrity,can provides us a physical model.2. The emphasis was on the SI/PI of several common simulation way. Mainly includes the S parameter model, the principle of eye diagram and measurement as well as the IBIS model. The IBIS model is one of the main tools in high-speed circuit SI simulation.It provided the simulation an effective way. In addition, in the high speed circuit the parasitic effect of via will have great effect on the circuit performance. In this paper, the equivalent model of via is established. Through the research and calculation of the via model, we can put forward the matters of attention for the layout of the wiring.3. With the widely used LPDDR2 in the cell phone chip circuit board, we run the PI and SI simulation validation. For the power integrity: mainly for the rationality of the power supply network. By analyzing the simulation results we conclude that adding decoupling capacitor in circuit, the actual measured PDN impedance decreases significantly. For the signal integrity: by extracting data channel parameters, weestablishing a simulation model. Through the eye diagram we judge each line of data transmission.Through the above research and verification, it emphasizes the importance of SI and PI in high-speed circuit design, as well as providing a theoretical and technical support for the later research.